Prepare Nopales: Boil water in a pot and add chopped nopales, onion, and tomato. Cook until tender.
Chop Vegetables: Chop onion and tomato into small pieces.
Brown the Meat: In a pot with oil, brown the ground beef, adding black pepper and salt.
Add Vegetables: Once the meat is browned, add chopped onion and garlic, and cook until fragrant.
Combine Ingredients: Add drained nopales, chopped tomato, and serrano peppers to the meat mixture. Season with salt and cook together.
Serve: Serve the mixture in tacos with beans and enjoy!