Preheat the oven to 350°F (175°C).
In a large skillet, brown the ground beef over medium heat until fully cooked.
Drain excess fat and stir in the taco seasoning, black beans, kidney beans, diced tomatoes, and corn.
In a greased baking dish, layer half of the beef mixture, followed by half of the sour cream and half of the cheese.
Repeat the layers with the remaining ingredients.
Top with crushed tortilla chips and the remaining cheese.
Bake in the preheated oven for 25-30 minutes, or until the cheese is bubbly and golden.
Let it cool for a few minutes before serving.
