In a large dutch oven, saute the onions, carrots and celery in a little olive oil.

When the onions begin to soften and change color, drain the liquid from the tomatoes into the pot. Then chop the remaining tomatoes into small pieces. Kitchen scissors work really well for this. (If using roasted tomatoes add enough water or vegetable broth to just cover the vegetables)

Add the garlic, bay leaves, oregano, any other seasoning you'd like plus salt and pepper.

Reduce the heat to very low and allow to simmer away...the longer the better.

Add more liquid if needed and reduce the heat some more because if you have to add more liquid it's probably too high.

When the sauce is the way you like it, remove the bay leaves and use a stick blender to puree the sauce.

Add a splash of balsamic vinegar to add a finishing touch.