Prepare the potatoes by peeling them if desired and cutting them into small, evenly sized cubes. Pat them dry to remove excess moisture.
Heat the olive oil in a large skillet over medium heat. Add the chopped onion and cook for 2–3 minutes, until softened.
Add the diced potatoes, paprika, Italian seasoning, garlic powder, salt, and black pepper. Stir well and cook for about 12–15 minutes, stirring occasionally, until the potatoes are golden and tender.
Stir in the minced garlic and cook for about 30 seconds. If using bell peppers or mushrooms, add them and cook until tender. Add spinach during the final 1–2 minutes if desired.
Make four small wells in the potato mixture using the back of a spoon.
Crack one egg into each well. Cover the skillet and cook for about 4–6 minutes, or until the egg whites are set and the yolks reach your preferred doneness.
Sprinkle the shredded cheddar cheese over the potatoes and eggs. Cover for about 1 minute, until the cheese melts.
Remove the skillet from the heat and garnish with fresh parsley and sliced green onions if desired.
Serve the skillet warm with your preferred breakfast sides.