Preheat oven to 400°F (200°C). Lightly grease a baking sheet or line it with parchment paper.
In a skillet over medium heat, cook ground beef until browned. Drain excess fat. Stir in taco seasoning and water; simmer for 2 minutes. Remove from heat.
Place one tortilla on the prepared baking sheet. Spread half of the cooked beef mixture evenly over the tortilla, followed by half of the black beans, 1 cup cheddar, and 1/2 cup Monterey Jack.
Top with another tortilla. Repeat layers with remaining beef, beans, and cheeses.
Bake in preheated oven for 12–15 minutes, or until the tortillas are golden and the cheese is melted and bubbly.
Remove from oven and let cool for 5 minutes. Slice into wedges.
Serve warm with salsa, sour cream, lettuce, tomatoes, black olives, and green onions on the side.
Notes
Customize with your favorite toppings like jalapeños, avocado, or extra cheese.