Prep. Preheat oven to 350 F and prepare an 8x8 casserole dish (I used an 8" round casserole dish) with cooking spray.
Saute veggies. Heat avocado/vegetable oil in a large pan over medium heat. Add diced onion, diced bell peppers, and sliced mushrooms. Cook until veggies are soft, and the liquid from the mushrooms has cooked off.
Assemble. Place veggies in the prepared casserole dish in an even layer and mix in 1 cup of cheese. Once the veggies have cooled slightly, pour the whisked eggs on top, and stir to combine.
Cook beef. Add ground beef or turkey to the pan and cook until no longer pink -- breaking the meat into small pieces as it cooks. Add tomato sauce, garlic powder, erythritol, sriracha, salt, and pepper to the pan and stir to combine. Bring sauce to a boil, then reduce to a simmer and cook for 5-7 minutes, or until hardly any liquid is left. When done, the meat will have a sloppy joe consistency.
Assemble + Bake. Add meat to the casserole dish in an even layer. Sprinkle the remaining 2 cups of mozzarella on top. Bake in the oven for 20 minutes, or until the cheese has melted. Sprinkle crushed pork rinds (if using) and sliced pickles on top before serving and enjoy!