Re-healthifying foods, anyone?

I've been on many, many diets in my life. Normally they're just calorie-counting, and last time I did Weight Watchers. They work just fine, but this time I honestly just want to lose fifteen pounds in order to keep from getting heavier than I am right now. I don't want to go on a big diet with all the emotional ups and downs diets bring. I just need to rein in the portion control a little, and stop saying that chips and dip qualify as dinner. I'm pretty good at healthy foods, but again I'm running into the whole too hot to bake casseroles problem. Does anyone have any really great suggestions for foods with which I can detox? I've just been having lots of stomach issues lately, and I want some nice, filling foods that will keep the hunger pangs from happening, and also that are rich in nutrients. I'm back to doing smoothies, which is great, but I need some good lunch and dinner options! Stovetop is all right if it's less than thirty minutes, microwave or small enough to bake in toaster oven is even better.

Judith's Super Easy Vegetables

1/2 large onion, roughly chopped
1/2 large zucchini, sliced
1 pound white mushrooms, sliced thick

Sauté all veggies with a few glugs of olive oil over medium heat until soft. Season with salt and pepper.