Preheat oven to 400°F. Spray large baking sheet with nonstick spray. Toss onion and next 5 ingredients together on prepared baking sheet; spread in single layer.
Sprinkle with salt and pepper.
Bake vegetables until tender and brown around edges, stirring occasionally, about 35 minutes.
Per serving: calories, 52; total fat, 1 g;saturated fat, 0.5 g; cholesterol,