Oven Tomato Sauce - cooking recipe

Ingredients

1 yellow onion, cut into chunks
6 garlic cloves, unpeeled
2 teaspoons italian seasoning
olive oil
3 lbs roma tomatoes
salt
pepper
1 tablespoon sugar
1 tablespoon balsamic vinegar
6 basil leaves

Preparation

Place a sheet pan on the middle rack in the oven and preheat the oven to 400°F.
Place the garlic cloves, onion, and Italian seasoning in a bowl and toss with 2 tablespoons of olive oil.
Core the tomatoes and cut them in half.
Carefully remove the hot sheet pan from the oven. Drizzle about 3 tablespoons of olive oil on the sheet pan and tilt and swirl to disperse.
Place the tomatoes flesh side down on the sheet pan. Add the onion mixture around the tomatoes.
Sprinkle with a heavy pinch of salt and a few grinds of pepper.
Bake for about 30-35 minutes, or until the tomato skins are wrinkly and the garlic cloves are soft.
Remove the sheet pan from the oven. Let cool for 5 minutes.
Carefully pull the skins from the tomatoes, leaving the tomatoes on the sheet pan.
Remove the skins from the garlic cloves and return to the sheet pan.
Sprinkle with sugar, balsamic vinegar, and a bit more salt and pepper. Mash the tomatoes a fork and stir to combine.
Bake for another 25-30 minutes until thickened and hot. Let cool 10 minutes.
Transfer to a blender or food processor, along with the basil leaves, and blend until smooth.