Fry bacon in a large cast iron skillet. Once cooked, removed the bacon from the skillet and set aside. Leave 2-3 tbsp bacon grease in the skillet.
Cook onions and garlic in the cast iron skillet over medium heat for 1-2 minutes. Add Brussels sprouts, sweet potatoes, salt and pepper and cook for 10 minutes, or until sprouts and potatoes begin to brown. Stir occassionally.
Move the cast iron skillet to the oven and bake for 10 minutes.
Remove the skillet from the oven and sprinkle bacon pieces on top. Create 4 wells in the hash and place an egg in each. Put back in the oven and cook 5-7 minutes, or until eggs are cooked to your desired doneness.