Preheat your oven to 200 C (400 F). Oil a baking sheet with 1/2 tablespoon of olive olive oil or just lay a piece of parchment paper on the baking sheet.
Heat a non stick pan on medium heat and add a splash of oil, when hot, add the ground beef, when cooked through, add the taco seasoning, and season with salt and pepper to taste. When cooked, drain oil.
Place the tortilla on the baking sheet, sprinkle with 1/2 cut of cheese, top with beef, then top with another 1/2 cup cheese. Bake until the cheese is melted, about 7 to 8 minutes.
Remove and sprinkle on remaining cheese, lettuce, tomatoes, and sour cream. Top with avocado if desired.