1 (4 ounce) can diced green chile peppers, drained
¼ cup fat-free milk
¼ cup light dairy sour cream
¼ cup refrigerated or frozen egg product, thawed or 1 egg, slightly beaten
Preheat oven to 350°F. Trim ends off tomatoes and remove cores. Cut tomatoes crosswise into 12 total slices (about ¾-inch thick each). Line a 15x10x1-inch baking pan with parchment paper. Place tomato slices and chopped onion in the prepared pan. Drizzle with oil. Sprinkle with garlic powder and ground pepper. Roast for 30 minutes. Remove from oven. Increase oven temperature to 400°F.
Meanwhile, combine corn muffin mix, cheese, chile peppers, milk, sour cream and egg product in a large bowl. Stir just until combined. Set aside.
Coat twelve 2½-inch muffin cups with nonstick cooking spray. Place a tomato slice and some of the onions in the bottom of each muffin cup. Spoon corn muffin mixture on top of tomato slices, filling muffin cups nearly full.
Bake for 15 minutes or until tops are golden brown and a wooden toothpick inserted into muffins comes out clean. Let muffins stand in cups on wire racks for 10 minutes. Run a thin metal spatula around edges of muffins to loosen from sides of pan. Invert muffins onto a serving plate. Serve warm.