Pasta sauce (tomato)

Dice one medium onion, 2 carrots, and 2 sticks of celery (proportions need not be exact, and adjust to taste). This is mirepoix. Heat a small amount of olive oil (enough to just cover the bottom of the pot) over medium heat in an 8 qt or so stockpot. Pour in the mirepoix and turn down the heat to medium low if it's sizzling loudly. Cook, stirring, until the vegetables are soft, about 10 mins or so. Turn the heat to high for a few seconds, then pour in a splash or two of vingear you like. If you can find tomato vinegar, use that - it's awesome. Cook over high heat, stirring, until the vinegar smell mostly dissipates, 2-3 minutes tops. Turn the heat back down to medium and add one small can of tomato paste. Stir to break up, and cook another 2-3 minutes, stirring periodically. Pour in 3 cans of crushed tomatoes with the juice. Use San Marzano tomatoes if you can find them. Bring just to a boil on high heat, then turn down the heat to low and simmer for about 40-50 minutes. If you like dried herbs, add them with the tomatoes. Oregano's good, and a little garlic if you like. Less is better than more - you can always add more later and they'll bloom in the sauce. After the tomatoes are cooked, stir in about 4-6 tablespoons of cold butter, 1 tablespoon at a time. This will enrich and thicken the sauce. Salt and pepper to taste, and if you like a sweeter sauce, stir in some sugar. If you want a smoother sauce, puree with a hand blender.