There are a bunch of variations on this theme, but if you stick the word "medley" in the title, it always works. I usually use rotisserie chicken for this...because I like EASY.
Step 1: Dig in your vegetable bin and see what you come up with. My favorite meals start with a bit of onion and red pepper...and since you are making a medley, you only need small amounts of each vegetable: zucchini, carrots, broccoli, green beans...all are excellent candidates, use what you like.
Step 2: Slice up your veg and sautee them in a some butter or olive oil.
Step 3: Make some rice or pasta. What do you have on hand? Cous-cous works great, and I've been known to make packages of Lipton's Side dishes in a pinch.
Step 4: Add cut-up chicken to vegetable mix and heat through. Season with your favorite seasonings. (A jar of pesto is awesome to have on hand to stir into your chicken/veg mix if you are serving this with pasta.)
Step 5: Make a bed of your rice or pasta, add the chicken/veg medley on top, serve with a side of toasted bread!
Elapsed time: 30 minutes, tops.
What I like about this is that you can serve it up so the little kids can separate out the things they like: they don't have to have it layered or mixed together. My zucchini lovers pick all the zucchini for their plates, leaving the broccoli and onions for someone else.
Don't have chicken? Substitute ham, smoked sausage, turkey, roast beef....
What are YOUR "default" dinners? This one is definitely mine.