potatoes and olive oil - I think these guys are your best bet here. When I cook the soup, cook the potatoes right in the stock. I give it a drizzle of olive oil at the end to give it some richness.

I like this soup - nice and creamy and vegan! I use frozen corn in place of the canned. A diced jalapeno is a nice addition.

http://vegweb.com/index.php?topic=10351.0

Coconut milk!

what about pureeing/blending silken tofu (be sure it's the "silken" kind) and adding it to the soup? i bet that would work out perfectly, and add extra protein to the dish. i've used it to make caesar dressing and mousse, and the texture comes out very smooth ...

This article is spot-on; root vegetables and gourds puree excellently into thick, creaminess. Also, there are plenty of vegan breads (ones that are marketed as "peasant" or "rustic" will often be vegan) that you can de-crust and puree into your soup which will give it some body and richness. I also second the olive oil comment.

I often use a roux to create a creamy texture for chowders. Add some water or stock (instead of milk) and you have a thick and creamy base to use.

Crescent Dragonwagon has a few in her 'Passionate Vegetarian' book, one (that I can't remember the name of) used silken tofu that was blended into the soup, and here's the other - getting a creamy soup using oats:

http://www.wellsphere.com/healthy-cooking-article/p-otage-of-asparagus-white-wine-lemon-or-creamy-asparagus-soup-made-with-oatmeal-for-souper-sundays/985864

Coconut milk is a wonderful way to add cream to soups, and get healthy medium-chain fatty acids into your diet (very important for both a vegan and a lactose-intolerant person). It works wonderfully in a butternut squash soup, or in a mixed vegetable soup, pureed or not.

Try my Sweet Potato and Radish Top Soup: http://tamingthetart.wordpress.com/2010/10/12/my-boyfriend-loves-meat. The butter can be swapped for more olive oil, parm can be omitted. So can the cream, which I normally wouldn't add to a squash soup, because I think they are creamy enough, but did here only because I needed to cut the spiciness.

Unsweetened Mimicreme is lovely. You can generally find it at Whole Foods and you can buy it from them at mimicreme.com

http://vegoutandabout.wordpress.com/

A good blender/masher will be key for you guys.
Pureed, fatted (olive oil or coconut oil or whatever takes your fancy), and thinned (veggie stock) white beans are a great cream substitute, as is cooked, thinned, and pureed oats. Not all with Celiac's can tolerate oats, I hear, but maybe it will work for you!

Try lentils! Combine with some broth, a can of corn, and some veggies, then blend the whole thing together. Lentils get creamy when cooked too long anyway. Try this family recipe for blended veggie soup: http://wp.me/p18BLq-p

I dabble in vegetarianism regularly (sometimes with the vegan thing) and my husband has celiac and we both have lactose intolerance to combat. I have to eat low fiber and low fat, though typically if I blend soups with fibery foods in them, I can tolerate them better. We make soup all the time in our house, and typically I use potatoes for the creamy factor and olive oil. Coconut milk is a great option for certain soups (we do a curry coconut milk squash soup that is great with fall squashes and gourds.) Pureed bananas can help thicken as well. This works great with fall soup flavors and doesn't turn out too pronounced, so instead of tasting only banana, you really only taste the squashes and apples and such, with a hint of banana sweetness. I like to use parsnips in blended soups, because the starchy component helps makes the texture creamy. Sweet potatoes, like regular potatoes, can help thicken things up and make the soup creamy and silky, but I actually find the combo of half sweet potatoes and half regular potatoes works best. I also use things like truffle oil or other flavored oils to amp up the decadence of the oil I'm using in place of butter. You can try using vegan replacement items like yogurt and cream cheese, though I find those items are typically better used cold, rather than heated in a fall soup. I have used vegan cream cheese in a cold cucumber soup before, and it worked great, but I tried to use it in a hot soup, and it lost its creamy texture and turned mealy, so I don't suggest it, though maybe there is a better way to work with substitutes when using them in hot items that I just don't know about yet. :)

Cornstarch is another thickener that can be used in place of a roux for soups that are starch-free, such as a tomato basil, and it will not impart flavor.

You just need to mix a tablespoon of cornstarch in with a cup of cold water and stir it until completely dissolved, then add at the end to the soup a little at a time until the thickness is what you would like. This also works for making gluten-free gravies.

The comments above are all super helpful and spot on. To make life easier, you may want to buy an immersion blender. You can pick up a decent one for under $20 and then you can puree the soup right in the pot.

I agree with all the comments about coconut milk. I just wrote about a really great Butternut Squash soup (with coconut milk, ginger and jalapeño papper) at my blog: www.diningatmydesk.com

Oh, that URL for the Butternut Squash Soup lives here. Thanks!

Roux will not work for someone with Celiac.

Soft silken tofu is shelf stable,and a great thickener for soups where coconut milk might be an unwelcome flavor, like a creamy broccoli or asparagus soup. Any soup with potato will blend nicely with an immersion blender, and you can control how smooth you get it. Use starchy rather than creamy potatoes.

Here's my recipe for Oven Vegetable Soup that has a velvety consistency, rich flavor and no cream. It is vegetarian, and vegan. http://therunawayspoon.com/blog/2009/11/oven-vegetable-soup/

cashews! blended raw cashews add a wonderfully mellow creaminess to soups. just soak raw cashews overnight (10-12 hours) drain and blend until smooth (maybe adding a little water to thin). then add to your favorite soup recipes as a cream substitute. Side note- raw cashew cheese is so easy to make and killer on pastas, sandwiches etc!

My all time favorite easy soup has three ingredients... leeks, broccoli, stock... and turns out creamy and luscious.

-Sweat 1 leek in a little oil till soft. Season with salt and pepper.

-Add a bunch of broccoli chopped into 1-2 inch pieces. (I use the stalk too, peeled.

-Add a quart of stock.

-Bring to boil, simmer till broccoli is fall-apart tender.

-Blend till smooth. Season again in needed.

Cauliflower can be substituted for broccoli and tastes like potato and leek soup.

@jazminecat, actually you can make a roux using oil (for the vegan factor) and a gluten free flour mix in place of regular wheat flour. I do it all the time for gravy and sauces, and it works great. It thickens the same and you can't tell from the flavor that anything is different than usual.

I second the coconut milk and the soaked cashews. Though, I've always heard cashews shouldn't be soaked more than 6-7 hours, because they will turn bitter. I find that four hours is enough time for them to soften up to be turned into a super smooth cashew cream with little water in a high speed blender.

Here's a lovely Thai red lentil soup with coconut milk from Ottolenghi. It's a staple at my house:

http://www.guardian.co.uk/lifeandstyle/2009/sep/26/thai-red-lentil-soup-new-vegetarian-yotam-ottolenghi

Also, I've made a roux with chickpea flour and coconut or olive oil, and it comes out great. It was for a chickpea gumbo so the flavor was appropriate, but I think there are puréed soup recipes that might also benefit from the nutty flavor. Also, there are plenty of other alternative flours to experiment with depending on the flavor profile you're going for. Rice flour might be a good relatively neutral one.

It's cool that you're making an effort to keep cooking together despite the challenge.

I just made a red lentil, coconut milk and thai yellow curry dish that could easily have been thinned into a soup (I served it over rice). All you're really looking for is gluten-free vegan food because all vegan food is lactose free.

Here's the recipe I spun off of (with some variation):
http://www.epicurious.com/recipes/food/views/Coconut-Red-Lentil-Curry-236684

Check out this carrot soup... it is AMAZING. Vegan and gluten free... the best.

http://www.crisiskitchen.com/2010/02/carrot-soup.html

Careful on the miso. That recipe specifies "light" which I believe uses only rice in the koji. Some miso uses barley as a starter, which is not gluten free. (I think this is called red; there is also a half barley half rice miso.)

You can also use cannellini beans -- they're soft and turn very creamy when puréed, plus they're super healthy.

Potato and carrot soup, with just a little bit of coriander to give it a kick. Sauté 2-3 large, diced potatoes and 3-4 large, diced carrots in a large pot, add about 4 cups of liquid (broth/water). Bring to a boil then leave to simmer, about half an hour. Add some coriander, to taste. Puré with an immersion blender and devour. Add some water/broth if soup is too thick.

Same recipe can be done by replacing the carrots with a couple of diced leeks and omitting the coriander.

Potatoes will make about just any puréed soup creamy and delicious.

pureed cauliflower also thickens nicely!

Seconding the silken tofu recommendation, and a tip: you can puree an entire package of silken tofu in a measuring cup with an immersion blender prior to adding it to your soup! This lets you blend in spices, too, and it lets you add creaminess to a stock without being as time-consuming as pureeing the whole pot.

I'm vegan and I've never used silken tofu to make creamy soups... interesting.
I usually make a roux if it's a chowder (using oil or vegan margarine, you can use a gluten free flour mix), use unsweetened nondairy milk, and stir in some cashew or sunflower seed butter (the latter is considerably less expensive to make, make it the same way as the cashew butter, described above- soak, then puree- also a good option for folks with nut allergies). A bit of nutritional yeast adds a cheesy flavour and thickens a bit. Tahini adds more umami flavour and creaminess. Miso, blended, adds body. Tapioca, corn, or arrowroot starch can be used to thicken a creamy soup or sauce. I usually use miso, tahini, nutritional yeast, and some sunflower butter when I want a cheesy, creamy soup like broccoli. It's all about learning the properties of different foods and using them in place of the usual standbys.

Adding bread to a soup recipe will increase the creamy texture, let the bread soak up some liquid and then puree it along with all the other vegetables. This could be gluten free is using gluten-free bread.
http://onionsandchocolate.wordpress.com/2010/10/06/creamy-gazpacho-andaluz/

The very simple Potato Leek Soup from the Joy of Cooking can't be beat. So easy, so delicious. My lactose-intolerant boyfriend's fave.

A delicious soup that fits the bill is the Moosewood Tunisian Pumpkin Soup--so tasty!

I've been doing this a lot lately- I will usually start with a roux made with flour and fat- usually either earth balance margarine which is vegan... or just olive oil. Then thickening later with this: soak 1 cup of raw cashews in enough cold water just to cover- in the fridge for a few hours then blend until it has the texture of heavy cream. It really works great.