Add tomatoes to a food processor.
Pulse until you get a smooth texture.
In a large saucepan over medium heat, add extra virgin olive oil, onion, carrots, bell pepper, mushrooms, celery and garlic.
Cook until onions soften and garlic becomes fragrant. About 3-5 minutes.
Add tomatoes and bring to a boil.
Reduce heat to low.
Simmer for 35-40 minutes. Vegetables should be soft.
Allow to cool.
Using the food processor, puree sauce.
Season to taste with salt and pepper.