Heat a large skillet over medium heat and pour in the olive oil. Allow it to shimmer for about 1-2 minutes.

Add the chopped onion and sauté for about 5 minutes until translucent. Stir in minced garlic and optional diced red bell pepper, cooking for an additional 2 minutes.

Stir in crushed tomatoes, dried oregano, red pepper flakes, and salt and pepper. Simmer on medium-low heat for about 10 minutes until thickened.

Create four wells in the sauce with a spoon and crack an egg into each well.

Cover the skillet and reduce heat to low. Cook for 5-7 minutes until the whites are set but yolks remain runny.

Remove the lid and garnish with fresh basil. Serve immediately with crusty bread.