1. Heat oven to 350ºF.
2. In 11x7-inch baking dish, spread chili evenly.
3. Remove papers from tamales; place tamales on top of chili. Sprinkle with onion and cheese. Bake 25 to 30 minutes or until heated thoroughly.
Note: To prepare in microwave, place chili in 1 1/2-quart casserole. Top with tamales; sprinkle with onion. Microwave on HIGH (100%) 4 minutes. Sprinkle with cheese; microwave 3 minutes longer. Cover; let stand 2 to 3 minutes before serving.