Heat oven to 450 degrees F.Set a large fine mesh strainer over a 4-quart saucepan and pour in the tomatoes, letting the juice run into the saucepan. Gently press on the tomatoes to extract any additional juice (Depending on the brand, you should have 4 to 5 cups tomatoes and 1 1/2 to 2 cups of juice.) Set the tomatoes aside.
Add the wine, vinegar, oregano, and pepper flakes to the juice, and bring just to a boil over high heat, stirring often.
Reduce the heat to medium-low and simmer, stirring occasionally until the liquid is reduced by half or until it has thickened to the consistency of tomato soup, 20 to 25 minutes. Remove from heat.
Meanwhile, toss the onion, carrot, celery, and garlic with the oil and salt in a small bowl then spread on a half sheet pan. Roast until the onions have begun to soften, about 10 minutes.
Remove the sheet pan from the oven and stir in the drained tomatoes and capers, and return to the oven to roast, stirring every 5 minutes, until the vegetables are softened and the tomato juices begin to darken and caramelize, 20-30 minutes.
Carefully transfer the tomato mixture to the saucepan. Use a hand masher or immersion (stick) blender to work the sauce to your desired consistency. Finish with the black pepper and season with additional salt if desired.
Serve immediately or let cool to room temperature, seal in an airtight container, and freeze for up to 1 year.