Melt butter in a skillet over medium heat. Add onion and pepperoni. Saute for 3-5 minutes. Add potatoes, tomatoes, oregano, spinach, and salt & pepper. Crack eggs into pan. Cover and cook for about 3-4 minutes. Serve with basil and dollops of ricotta cheese.
Recipe by Rachel Schultz at https://rachelschultz.com/2012/12/05/pepperoni-egg-skillet/