A great brunch recipe: this dish is so warming and comforting! Compared to commercial eggs, pasture-raised eggs have five times more vitamin D, two-thirds more vitamin A, 2 times more omega fatty acids, three times more vitamin E, and seven times more beta carotene.
Preheat the oven to 350°F. In a large cast iron skillet or a large pan, melt about 1 tbsp of butter or ghee over medium-high heat. Cook the sausage until brown and crumbly, about 3 to 5 minutes. Remove from the skillet and set aside.
Add the sweet potatoes and stir about every minute so they don't burn, for about 3 to 4 minutes. Then add the onion and sauté until they are translucent. Add the rosemary, salt, and pepper (and chili flakes, if desired).
Turn down the heat to medium and add the spinach. Add the sausage back in and stir to combine. Crack 4 eggs onto the top of the dish.
Add the entire skillet to the oven and bake for 20 minutes. Serve warm.