Preheat your oven to 350°F (175°C). Gather all ingredients and utensils, including a 9x13-inch casserole dish.

Chop the sweet potatoes into uniform ½-inch cubes. Dice the onion and green pepper, and mince the garlic. Lightly grease your casserole dish.

Heat about a tablespoon of avocado oil in a Dutch oven over medium heat. Add the sweet potatoes, onion, and green pepper, sautéing for 8-9 minutes until tender. Stir in the minced garlic for an additional minute.

Remove vegetables from heat. In the same Dutch oven, add the turkey sausage, breaking it into crumbles. Cook for 5-6 minutes until browned.

Transfer the sausage to the casserole dish along with the sautéed vegetables. Mix them together to create an even layer.

In a separate bowl, whisk the eggs, milk, thyme, salt, pepper, and half of the shredded cheese until well-blended.

Pour the egg mixture over the sausage and vegetables in the casserole dish, gently stirring to distribute the egg evenly.

Bake for 40-45 minutes until the center is firm and the top is golden brown. Cover loosely with foil if browning too quickly.

Allow the casserole to rest for 5-10 minutes before slicing and serving warm.