In a medium size bowl, mix the crust ingredients together. Coat an 8×8 or 9×9 inch baking dish with cooking spray (I use a paper towel to wipe the bottom and sides with coconut oil). Spread the mixture evenly over the bottom of the dish.
Bake the crust for 5 minutes. Remove from the oven and set aside.
In a large pan, brown the ground sirloin, breaking it apart as you cook it. Once cooked through, remove from pan and set aside. Bring pan back up to medium heat and saute the diced onion in olive 1 tsp oil until translucent. Add garlic, green pepper, mushrooms, tomato, Italian seasoning, pepper, and salt. Cook for 10 minutes, or until veggies have softened and water has cooked off. Add the ground sirloin and tomato sauce, then stir to incorporate.
Taste and adjust salt if needed. Pour pie mixture evenly over crust. Cover with mozzarella, and bake for 15 minutes or until cheese is melted, golden, and bubbly. Remove from oven, and let sit for a few minutes before serving. This allows the pie filling to set up, so that it doesn’t spill all over your plate when served.