Heat ½ cup extra-virgin olive oil in a large saucepan over medium. Cook 5 garlic cloves, finely chopped, stirring, until golden, 30–60 seconds. Add 14 oz. Sun Gold tomatoes, halved through stem ends, and 1½ tsp. Diamond Crystal or 1 tsp. Morton kosher salt, ½ tsp. crushed red pepper flakes, and ½ cup boiling salted water from pot; season with freshly ground black pepper. Cook, stirring occasionally and smashing tomatoes with a wooden spoon, until tomatoes are jammy and falling apart, 5–7 minutes.