Heat the olive oil in a large skillet over medium heat. Add the chopped onion, celery, and carrot. Sauté for about 5 to 7 minutes, until vegetables begin to tenderize. Reduce the heat to low, stir in the parsley and minced garlic. Cook until the vegetables have softened, about 10 to 15 minutes more.
Add the whole tomatoes and their juices, crushing them with your hands as you add them into the pot or break with the side of a wooden spoon in the pot. Stir in the tomato paste, dried basil, and dried oregano (if using). Season with salt and pepper to taste.
Reduce the heat to low. Allow the sauce to simmer for about 20 minutes, uncovered. Cook until the sauce has thickened.
Puree with an immersion blender, if desired. Serve immediately.
Notes
Optional: Add a pat of butter at the end of cooking.
*Nutrition calculation does not include the added salt "to taste".