Heat the Olive oil in large pot over medium heat.
Add the onion and cook until translucent.
Add Garlic and cook for another minute. Careful not to let the garlic burn or it will have a bitter taste.
Stir in the crushed tomatoes, dried oregano, and dried basil.
Add a sprig of fresh rosemary.
Season with salt and black pepper to taste.
Let simmer on low heat for at least 30 minutes, stirring occasionally.
Remove the rosemary sprig before serving.
Garnish with fresh basil leaves.