Heat the oil in a large skillet and add onions and mushrooms. Cook until translucent.
Add ground turkey to one side of the pan and cook until no longer pink.
Add in taco seasoning, tomato paste, water. Simmer about 10 mins and set aside.
Preheat oven to 350 degrees.
Add a little olive oil to the bottom of the baking dish.
Cut each large tortilla into 4 pieces. Lay tortillas piece on the bottom of baking dish.
Layer one third of the meat mixture over the tortillas.
Sprinkle 2 ounces of shredded cheese over the meat.
Layer tortilla pieces on top and repeat the process two more times.
Top with the last 5-6 tortilla pieces and sprinkle cheese on top.
Bake for 25-30 minutes.
Allow to cool for 20 minutes before serving
Top with sour cream and avocado if desired.
