Belle’s Pomodoro Sauce

• 2 cans (each 28 oz/800 g) whole San Marzano tomatoes with juices
• ¾

In a large, deep frying pan or saucepan over medium heat, combine the tomatoes and their juices, butter, onion halves, garlic, Parmesan rind, and 2 teaspoons salt. Bring to a simmer and cook, uncovered, stirring occasionally and crushing the tomatoes as they cook down, until the tomatoes are mostly crushed and the sauce is reduced slightly, 1-1½ hours. Remove the pan from the heat and discard t