Preheat your oven to 375°F and lightly grease a 9x13-inch baking dish with a small amount of olive oil.
Peel and cube the sweet potatoes into 1/2-inch pieces, then steam them for about 6 minutes until they are slightly tender.
Heat the olive oil in a large skillet over medium heat and sauté the diced onion and red bell pepper until they become soft.
Add the ground turkey sausage to the skillet, breaking it apart with a wooden spoon, and cook until it is completely browned.
Stir the baby spinach into the sausage mixture until it just begins to wilt, then remove the skillet from the heat.
In a large mixing bowl, whisk together the whole eggs, liquid egg whites, Greek yogurt, and cottage cheese until the mixture is smooth.
Whisk in the sea salt, black pepper, garlic powder, and dried oregano to evenly distribute the seasonings.
Layer the steamed sweet potatoes and the sausage-vegetable mixture into the bottom of the prepared baking dish.
Pour the egg mixture over the top, ensuring all ingredients are covered, and sprinkle the shredded cheddar cheese across the surface.
Bake for 40 to 45 minutes until the center is set and the top is golden brown, then let it rest for 10 minutes before slicing into 8 portions.