Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish with avocado oil.

In a large skillet, heat 2 tbsp of avocado oil over medium heat. Add chopped onion, green bell pepper, and sweet potatoes. Sauté for 8-9 minutes until softened. Stir in minced garlic for the last minute.

In the same skillet, add turkey sausage and cook until browned and fully cooked, about 5-7 minutes. Combine with vegetable mixture in the baking dish.

In a mixing bowl, whisk together eggs, milk, dried thyme, salt, and pepper until smooth. Fold in mozzarella cheese.

Pour the egg mixture over the sausage and vegetable layers in the baking dish. Bake uncovered for 40-45 minutes or until the center is firm.

Let the casserole cool for about 15 minutes before slicing and serving warm.