Preheat oven to 325 degrees F.
In 2 (13 by 9-inch) pans place tomato halves cut side up. Sprinkle with oil, salt and pepper, onion
, and herbs
. Bake tomatoes
for 2 hours. Check the tomatoes after 1 hour and turn down the heat if they seem to be cooking too quickly. Then turn the oven to 400 degrees and bake another 30 minutes. Remove from the oven and process tomatoes through a food mill
on medium dye setting over a small saucepan
. Discard skins. Add white wine
, bring to a boil, reduce heat to low and cook for 5 minutes.