Preheat the oven to 400 degrees. Place tomatoes on a baking sheet, sprinkle with the olive oil, salt, pepper, and toss with your hands. Arrange the tomatoes in a single layer, cut side up, on the same baking sheet and roast for 45-55 minutes.
In an 8 quart stockpot over medium heat, saute the onions, garlic, and crushed red pepper in the olive oil and butter for 10 minutes or until the mixture starts to brown.
Bring to a boil and simmer uncovered for 50 minutes. Pass through a food mill with a coarse blade. Adjust seasonings. Enjoy with good friends and a crusty baguette!