adapted by http://theresalwaysthyme.blogspot.com/
3 pounds fresh tomatoes (mix of any kind you like, heirlooms are great)
6 cloves garlic, peeled
1/4 cup olive oil
salt and pepper
Combine ingredients on a half sheet pan. Roast at 300°F for about 2 hours, until tomatoes get soft and caramelized. Let them cool, and run through a food mill to remove skins and seeds. The resulting puree will be nice and thick.
Season to taste with salt and pepper.
You can freeze it for later or use it for anything you like, sauce or soup, add herbs or whatever seasonings. You can also roast the tomatoes with sliced onions