Heat the olive oil in a skillet over medium heat until shimmering and fragrant.
Add the chopped red onion and sliced bell pepper to the pan, sautéing until they soften and become slightly caramelized, about 5 minutes. Stir occasionally to prevent sticking and encourage even cooking.
Stir in the diced tomatoes and cook until they release their juices and create a chunky sauce, about 3 minutes. The mixture will look saucy and vibrant, with the vegetables melding together.
Add the harissa paste, stirring thoroughly to coat all the vegetables evenly, releasing a smoky aroma and deep red color. Cook for another minute to let the flavors meld.
Create four small wells in the sauce using a spoon, then carefully crack an egg into each well, spacing them evenly across the skillet.
Season the eggs with salt and pepper, then cover the skillet with a lid or aluminum foil and cook on low heat until the egg whites are just set, about 4-5 minutes. The yolks should remain slightly runny for best texture.
Gently remove the skillet from heat once the eggs are cooked to your liking and serve hot, ideally with crusty bread or a side of yogurt to balance the spice and savor the rich sauce.
