Prepare vegetables as directed and layer in a casserole dish, all except for the tomatoes. Combine ingredients for the sauce (salsa, basil, garlic and mustard) and pour over the layered vegetables. Place sliced tomatoes over the top. Cover and bake at 325 degrees for 45 minutes. Remove cover and bake for 15 minutes longer.
Helpful Hints: Serve with grains such as brown rice or bulgur wheat.