Preheat the oven to 350°F (175°C).

In a skillet over medium heat, cook the ground beef until browned. Drain excess fat.

Add the black beans, diced tomatoes, and taco seasoning to the skillet. Stir to combine and cook for 5 minutes.

In a baking dish, layer half of the crushed tortilla chips, followed by half of the beef mixture, and half of the cheese. Repeat the layers.

Bake in the preheated oven for 20 minutes or until the cheese is melted and bubbly.

Remove from the oven and let cool for a few minutes before serving.

Serve with sour cream and garnish with sliced green onions.