In a large skillet or saucepan, heat the olive oil over medium heat.
Add the finely chopped onion to the skillet and sauté for about 2-3 minutes until translucent.
Stir in the tomato paste and continue to cook for another 2 minutes. This will allow the tomato paste to caramelize slightly, enhancing the flavor of the sauce.
Now, add the can of crushed tomatoes, dried basil, dried oregano, salt, and pepper to the skillet. Stir well to combine.
Reduce the heat to low and let the sauce simmer for about 15-20 minutes, stirring occasionally. This will help the flavors meld together and the sauce to thicken.