you could make some vegetarian italian dishes like lasagna or eggplant parmesan as the main. As a side dish I'm positively obsessed with fennel cooked in cream.

recipe - mix 2 fennel bulbs (broken down and cut into fork size pieces) with 2 cups of heavy cream, 1 cup parmesan cheese, salt and pepper. Pour this into a baking dish and dot top with 4 tablespoons butter cut into pieces. Cover and cook for an hour at 425. then uncover dish, sprinkle with 1/2 cup more parmesan and bake for another 30 minutes.

As a vegetarian cook, I do love the presentation of stuffed squash (looking for a centerpiece dish? Stuff a whole pumpkin!) but I also love tarts, galettes, and quiches. They're easily assembled ahead of time, leaving you less stress on busy days, and can be filled with just about anything. The last one I made contained spinach and aged gouda, but I think my favorite this season combined sliced peaches, rosemary, and gruyere! Here's a good basic quiche recipe. http://find.myrecipes.com/recipes/recipefinder.dyn?action=displayRecipe&recipe_id=10000001901966&cookbook_id=5168475

maybe this falls into the "stew" category... but the mushroom bourguignon recipe on smitten kitchen is SO SO SO good. you can make it with vegetable broth (instead of beef broth) to make it completely vegetarian.

I'm not a vegetarian, but I dearly love beans.

Arrozos de Verduras, and Black bean and sweet potato burritos look & taste great together.

If you want to avoid the casserole effect, you could serve the same recipe, just make them as tacos instead of burritos.

Because vegetables don't come in large hunks like meat, you're going to end up with a stew or pasta or casserole or other mix of things that you make look glitzy by how you serve it.

I'm still a fan of mushroom-cranberry pasta in basil cream sauce. The cranberries look festive, the flavor is wintry, and you serve it in a pretty bowl with a garnish.

You MUST try this:
http://www.epicurious.com/recipes/food/views/Butternut-Squash-Gratin-with-Goat-Cheese-and-Hazelnuts-240412

I've brought this dish to many holidays parties and get asked for the recipe every time.

Seriously. It's delicious.

I had two Thanksgiving dinners this year and provided a vegetarian main dish for each. For one, I made Melissa Clark's Butternut Squash and Mushroom Wellingtons. For the other, I made Butternut Squash and Apple Galettes (I had a glut of butternut from my CSA): http://tamingthetart.wordpress.com/2010/09/30/sorry-baltimore-i-blame-the-galette. Both were delicious, and I think you could easily adapt to include other ingredient combinations.

I really loved "Pumpkin Stuffed with Everything Good" by Dorie Greenspan for a festive vegetarian main course. I've used a variant with caramelized leeks, fresh sage, gruyere and no bacon stuffed into sweet dumping squashes for individual servings, but a kabocha would be a wonderful centerpiece dish.

http://www.epicurious.com/recipes/food/views/Pumpkin-Stuffed-with-Everything-Good-361169

My husband and I have been in search of the same thing, and just made this vegetarian nut loaf made of nuts, cheese, mushrooms, onions and herbs -- it's a perfect vegetarian centerpiece for a holiday meal! It's great for vegetarians and meat-eaters alike, looks festive, and is incredibly delicious! We posted on it here:

http://www.acouplecooks.com/2010/12/vegetarian-nut-loaf/

My mom makes spinach crepes as the main course for our veggie Christmas every year, and I've always thought that they were fairly stylish looking.

http://www.oregonlive.com/mix/index.ssf/friday_night_dinner_party/vegetarian-recipes-for-your-holiday-table.html

Some good options here. The beet wellingtons in particular look very 'main dish' to me.

I made samosas stuffed with sweet potatoes and feta:

http://abcdsofcooking.blogspot.com/2010/12/samosas-3-kinds.html

We've done a couple of festive vegetarian recipes for holidays. A nut roast/nut meatloaf one year, and one year we did a gougere ring filled with roasted peppers that was very Christmassy. Another one I love is Giada's Veggie Meatloaf with Checca Sauce - so delicious - recipe is on the food network website.

I'm vegetarian also, and I always do a harvest lentil loaf. Usually has some combination of walnuts, finely chopped apples, celery, carrots, onions, lentils, eggs, bread crumbs, and cheese and for thanksgiving I added a pear in! I top it with parmesan and looks beautiful if you have a nice dish to cook/serve it in.

I made this Nut stuffed Delicata Squash dish! The sage, nuts & cheese mimic the taste sausage! It was fantastic. My meat eating husband asked for seconds!

http://www.shutterbean.com/nutstuffed-delicata-squash/

This is my first holiday as a vegetarian (I skipped Thanksgiving) so this is a great post to be reading! My family makes prime rib for Christmas Day so I need something tasty to make for me that will make them jealous. :)

Luckily, I don't have to worry about Christmas Eve. We make pierogies and I was thinking of making some sweet potato latkes to go with. I've always liked Christmas eve better anyway...

Seitan en croute is my new go-to holiday dish. My assorted family loved it at Thanksgiving and raved about how pretty it was. (Assuming you mean veggie as short for vegetarian and not vegetable.)

It was good in a leftover sandwich, too.

http://justthefood.blogspot.com/2009/10/truth-is.html

Have you ever been to Follow Your Heart in LA? They make a great tofu/wheat loaf. They now have a recipe book with this particular recipe in it, as well... along with other great vegetarian holiday foods.

In the past, I have prepared this Chanterelle Bread Pudding as a vegetarian entree option. This dish is seriously delicious and substantial. The mushrooms give it a meatiness sans the meat.

Enjoy!
Brandon

Seitan is perfect for these occasions, and if you want to avoid the meaty texture, try these chickpea cutlets with a mushroom and wine gravy. I arrange them on a long, narrow white serving dish, pour a generous ribbon of the gravy down the middle and serve with green vegetables and roasted potatoes.
http://www.food.com/recipe/chickpea-cutlets-283551