Cut sausage and onion into bite-sized pieces.
Add olive oil to a pan and stir-fry the sausage.
Add onion and bell pepper and stir-fry together.
Add tomato sauce and bring to a simmer.
Make a space in the center and crack the egg into it.
Cover and cook until the egg is half-cooked (soft-boiled).
Season with salt and pepper to taste.