Preheat the oven to 350°F (175°C).

Sauté the sweet potatoes, onion, green pepper, and garlic in a skillet over medium heat for 8-9 minutes until soft.

Spread the cooked vegetable mixture evenly into a greased 9×13-inch casserole dish.

In the same skillet, cook the turkey sausage until fully browned, about 5-7 minutes.

Combine the sausage with the sautéed vegetables in the casserole dish.

Whisk together the eggs, milk, thyme, salt, pepper, and shredded cheese until frothy.

Pour the egg mixture over the sausage and vegetable blend and gently stir to combine.

Bake in the preheated oven for 40-45 minutes until the center is firm and lightly golden.

Let the casserole cool for about 15 minutes before serving.