Slow-roasted Garlic-Tomato Sauce

Method

1. Line two 9x13-inch rimmed baking sheets with parchment paper; set aside. Preheat oven to 275°F; place oven racks in third and fourth positions.
2. Rinse and remove stems from tomatoes; place on clean dishtowel then roll tomatoes around to dry; if using larger tomatoes, cut in half or quarters; place tomatoes and any liquid in large bowl.
3. Rinse bell peppers then remove stem, ribs and seeds (leave in ribs and seeds if you want a spicy hotter sauce); slice peppers in half; rinse again then dry.
4. Peel onion and slice into 4 chunks and pat dry.
5. Peel garlic and add to bowl; drizzle on oil and stir to coat all.
6. In a small bowl or jar with lid, combine light brown sugar, sea salt and black pepper; whisk or shake jar to combine; sprinkle over oiled vegetables and stir to coat evenly.
7. Place onion sections and bell peppers (skin side down) on prepared baking sheet; spread tomatoes and garlic on second prepared baking sheet; place sheet with tomatoes on the lowest of the two oven baking racks and the sheet with peppers the next rack up.
8. Bake for 1-1/2 hours at 275°F then increase oven temperature to 325°F and bake for 30 minutes.
9. Remove sheets from oven to cool for at least 5 minutes; lift parchment paper sheets and pour contents (including liquid) into the bowl of a food process or blender, or place in a large bowl and mash with a potato masher. Process peppers, onion, garlic and tomatoes to desired consistency; serve immediately as a warm sauce, or pour sauce into a glass jar with an airtight lid and refrigerate up to 2 days; serve cold or reheat in a saucepan set over medium heat.