Directions

1. Preheat oven to 450 degrees F (230 degrees C).
2. Pour 2 tablespoons of vegetable oil into a large bowl; toss the potato slices in the oil to coat.
3. Arrange the slices in a single layer on a baking sheet and sprinkle with salt and black pepper.
4. Bake in the preheated oven until the potato slices are golden brown, about 20 minutes.
5. While potato slices are baking, heat 1 tablespoon of vegetable oil in a skillet over medium heat; brown the ground beef in the hot oil, breaking it up into crumbles as it cooks, 8 to 10 minutes. Drain excess grease.
6. Mix the black beans into the ground beef; stir in the taco seasoning and water. Bring the mixture to a boil and reduce heat to medium-low. Simmer until the flavors have blended, about 10 minutes.
7. Arrange the potato slices on a serving platter and sprinkle with half the Cheddar cheese.
8. Top the potatoes with the meat and bean mixture; sprinkle the remaining cheese on the nachos.
9. Spread the lettuce out over the nachos and garnish with tomato and dollops of sour cream and guacamole.