My kids love this broccoli so much I call it "magic broccoli." It's also super easy to make. Combine it with some rice and or pasta and chickpeas from a can (separate, if their foods can't touch!) and you have a quick and healthy meal.
http://outoftheordinaryfood.com/2012/03/20/magic-broccoli/

My standby is this simple tomato sauce, served with pasta. You can add any veg your kids like, or some beans for protein, or grate some cheese on top...
http://outoftheordinaryfood.com/2011/11/08/simple-tomato-sauce/

And just last week I made this "vegetable soup my boys like." Also very simple, brothy, a tiny bit sweet, and featuring corn, peas, carrots and potatoes, because those are crowd-pleasers, but you could adjust to your kids' tastes. Also quick to make, and you could serve over pasta or rice, or with cheese and crackers.
http://outoftheordinaryfood.com/2012/12/23/vegetable-soup-that-my-boys-like/

Put rice to cook in the rice cooker. Heat olive oil in a skillet, lightly dredge skinless chicken thighs in flour with some ground in black pepper, brown in skillet, add some chopped onions when you turn them, add liquid to half way, turn down the heat, slap on the lid, simmer until rice is done. Options to add in whatever combinations strike your fancy: garlic, ginger, honey, carrot chunks, tomatoes, soy sauce, wine, apple or orange juice, bay leaves, oregano, basil, dill. Add a green vegetable and you've got an easy, flexible meal in 30 minutes.

I don't have kids, but I've become a huge fan of tossing good old boneless chicken breasts into the slow cooker in the morning. When I come home from work it shreds beautifully and can be whipped into pasta, casseroles, soup, enchiladas, etc, in no time!

My kids will eat anything in soup.

Meatballs are also good. Traditional ones are nice, but I make a ton of different kinds--kefta, Asian flavored ones, Indian spiced. I tend to make something starchy to go along with them, which kids tend to love. A green vegetable rounds things out nicely. Plus you can make big batches and freeze them.

Frittatas are also popular in my house. They're also great to use up leftovers. Add a salad for yourself.

Sorry to post again, I keep thinking of others!

My kids love to dip raw veggies in hummus. I make this one type of hummus that tastes a bit like catsup, and I oven-roast some french fries, cut up some red peppers, maybe a bit of tomatoes and pita...
http://outoftheordinaryfood.com/2012/09/09/roasted-rosemary-fries-and-spicy-tomato-hummus/

Another quick and easy meal is tacos...warm up some flour tortillas, make some rice, and make a quick stirfry of beans and broccoli... Sometimes the kids just eat tortillas, rice and cheese, but they'll usually have some beans and broccoli as well...
http://outoftheordinaryfood.com/2012/05/14/black-bean-and-broccoli-tacos/

And finally, here's a pizza my son invented. It's got toasted beets, so he calls it beezza!
http://outoftheordinaryfood.com/2012/03/22/beezza/

I promise to stop now!! This is a question I deal with every evening!!

We are a mac & cheese family! I use a basic Panera knockoff recipe, and make my own changes, like adding meat and/or veggies or changing cheeses. I made a taco mac last weekend with my 3yr old's help. He loves to cut veggies, add things to the pan, and stir.

Here's the basic recipe, it makes a ton, enough for a family of 3-4 to eat two meals, I usually do the first meal as a stovetop mac, and then bake the leftovers a few days later.
http://smells-like-home.com/2012/02/paneras-stove-top-mac-and-cheese/

I do a lot of stir fries and rice--we have a rice cooker, so I set that up (can do on timer if you're coming home right before dinner) and then I just fry up some chicken and vegetables and season it.

If you're willing to do advance prep, and your kids like it, you can premake lasagna or baked ziti in 8x8 pans, and freeze. If they'll eat soups or stews, you can do the same (minus potatoes). My goal if I'm the only adult home is to minimize the time I'm actively at the stove--that's just when they'll get themselves into trouble. Advance prep is my friend. Also the oven.

We like pasta and pesto, frozen cubes of homemade pesto. Just add a frozen cube with hot pasta and dinner is done. Sometimes I throw broccoli florets in with the past for the last few minutes, or I just cut up an apple to go with the meal.

The kids are also amused by breakfast for supper, so sometimes I will just make eggs and toast or pancakes.

i think it's an american thing to think kids don't like certain things. travel & you'll see kids eat all kinds of exotic complex foods.

as long as it's safe, give them what you're having.

Inspired by this: http://www.nytimes.com/2009/04/01/dining/01mini.html?_r=0, we do "chickpea pancakes".

Our recipe base recipe is:
1 c. chickpea flour
2 t baking powder
salt, pepper, and turmeric
mix

Add 3/4 to 1 c. water to desired consistency

Heat a generous amount of olive oil in a frying pan over medium heat and pour a small pancake-sized amount of batter into the oil. Add a protein (we do crumbles of tofu but leftover chicken chunks are nice) and vegetable (spinach or maybe peas — usually we grab frozen and defrost for 30 seconds in the microwave) in the pan. Flip when brown and brown on the second side.

It's super fast with protein, starch, and veg all together. We toss sauce on the side — our kids like salsas or chutneys, less adventurous guests are likely to get ketchup. This is our most-requested kid dinner by far. If we just need enough for 1 kid, half the recipe. It doubles and quadruples, too, of course.

Once clarification: we add the protein and vegetables into the pancake, but we do so once it's in the pan. This is easier for us than the method of putting the fixin's in first and pouring batter on top. -m

I frequently eat alone with my son because of my husband's job. He's older now, but we have several standbys (a lot of which are mentioned above!)

One thing I often do - eat leftovers. Kids don't care if you ate it yesterday, and that way you don't have to fuss so much.

Other easy ideas: Put whatever leftovers you've got into a quesadilla. Easy-peasy.
Soup and sandwiches - tomato and grilled cheese are a fave. Even if your kid won't eat soup (mine won't) they probably like to dip. (Tomato soup can be made from scratch with canned tomatoes, milk and cornstarch.)
Believe it or not, shrimp and scallops are quick and easy (provided you buy them shelled and trimmed) just saute them quickly (garlic and lemon optional) and serve over rice (I keep frozen cooked brown rice for this purpose) you can add cut-up peppers or snow peas to the saute.
Don't forget not to cook: salads and raw veggies with dip with cheese or sausages are great in the summer.

Is one of the challenges getting motivated to cook? I know when my husband isn't joining us for dinner, I feel a lot less motivated to make an effort cooking because my son literally doesn't care. He is totally happy eating a bowl of fruit with nothing else, so making more effort than that (and possibly having him decide not to eat anything that night!) always seems sort of disheartening. For me, I try not to fight that feeling. If I feel ambitious I'll make something more involved, but if not I just go with it and strive for something easy and relatively balanced. We might have lunch meat sandwiches, eggs, mac and cheese, cheese and crackers, peanut butter with bread or crackers, oatmeal, etc. Add some veggies or fruit and it's a meal. We also eat leftovers a lot. Make a big batch of something when your husband is around and you feel more motivated, and then reheat 1 or 2 times for dinner for you and your kids.

I had a shift working hubby for years and cooking alone is a pain.
a couple favourites at our place with the kids are:
Chicken Adobo http://kaleeats.blogspot.ca/2012/03/chicken-adobo.html
Sausage Potato Bake http://kaleeats.blogspot.ca/2012/11/sausage-apple-potato-bake.html
one of the best sites for ideas is http://www.dinneralovestory.com/
hope this helps!