Chili Pie With Cornbread Crust

Name: Chili Pie With Cornbread Crust
Ingredients: 4 tbsp. vegetable oil; 1 lb. ground beef chuck (85% lean); 1 large onion, finely chopped; 2 medium bell peppers, seeded, chopped; 2 cloves garlic, chopped; 1 tbsp. chili powder; 1/4 tsp. ground chipotle chile; 1 can (14 ounces) fire-roasted diced tomatoes; 1 can (14 ounces) kidney beans, rinsed and drained; 1 can (14 ounces) fat-free refried beans; Salt; 2/3 c. fine- to medium-ground cornmeal; 2/3 c. all-purpose flour; 1 tsp. baking powder; 1 large egg; 2/3 c. milk; 2 serrano chiles, thinly sliced; Fresh cilantro, for garnish