You can't make too many vegetables, in my opinion... but to fill a big double-thick cookie sheet try this:
1 large sweet potato, peeled and cubed
1 large zuchinni, cubed
1 medium sweet onion, 1-inch chunks
3 small tomatoes, quarterd (I find canned stewed tomatoes work better than fresh, which will weld themselves to the pan if you're not careful)
1 cup frozen cruciferous vegetable of choice (broccoli, cauliflower, or halved brussels sprouts).
Cook your sweet potato chunks covered in the microwave for 3 minutes, until tender. (trust me on this one, crunchy sweet potatoes will ruin the whole thing)
Toss all the veggies in olive oil and lemon pepper until they seem well coated. Roast at 450 until edges are browned and the house smells good (about 30-45 minutes). Don't burn your tongue, and try to share with your loved ones!