Heat the olive oil in a large saucepan over medium heat.
Add the chopped onions and garlic, and sauté until they become translucent.
Add the ground beef and cook until it's browned and no longer pink, breaking it apart with a spoon as it cooks.
Stir in the crushed tomatoes, tomato sauce, basil, oregano, salt, and pepper.
Reduce heat to low, cover, and let the sauce simmer for about 30 minutes, stirring occasionally.