Take a 9x13-inch baking dish with oil and set it aside. Now put a rack in the middle of the oven and heat the oven to 360 F.

Take a high-sided and large skillet and heat 1 tablespoon oil in it over medium-high heat.

Add beef to the skillet and cook for 6-8 minutes until browned.

Transfer the beef to a plate and drain extra fat from the skillet.

Now add 1 tablespoon of olive oil and heat over medium flame. Add onion, garlic, pepper, and cook them for 5 minutes or until softened. Keep stirring.

Then add beans, beef, chili powder, tomato paste, oregano, cumin, pepper, and salt. Stir to combine and cook for 2 minutes.

After that, turn off the heat and stir in salsa and half cheese. Transfer this mixture to the baking dish and spread it into an even layer. Sprinkle the remaining cheese.

Bake for 20 minutes and cheese is melted. Remove from the oven and let it sit for 5 minutes.

Your Beef Taco Casserole is ready. Top with tomato and lettuce and serve with sour cream or Greek yogurt.