Created by Sue on February 18, 2013
Step 1: Brush onion with oil and place cut side down on a nonstick foil lined baking sheet. Roast at 450F for 20 minutes, then flip over, brush with a little more oil, then roast until the onion "pops" and looks caramelized and ruffled like a rose.
Step 2: Pulse tomatoes in a food processor until they resemble chunky salsa.
Step 3: Place all ingredients in a saucepan and simmer over low heat until reduced by half, about an hour.
Step 4: Puree sauce in food processor (in batches if necessary) and cool before using, or reduce further by simmering until it is your desired consistency.
Step 5: Freeze any unused portions for use later.