Preheat oven to 350 degree F. In a 1-1/2-quart casserole combine vegetables, cheese soup, and thyme. Stir mashed potatoes to soften. Spread mashed potatoes carefully over vegetable mixture to cover surface.
Bake, covered, in preheated oven for 30 minutes. Uncover and bake about 15 minutes more or until heated through, topping with cheese for the last 5 minutes of baking. Serve in shallow bowls. Makes 4 servings.