Step 2: Simmer the sauce
Sauce
- whole peeled tomatoes800 g1 28oz can
- onions, yellow or white1
- butter, unsalted70 g~5 tbsp
- saltto taste
Add the tomatoes, butter, peeled onion halves, and a small pinch of salt to a large skillet over medium-low heat.
- A wider skillet sauce more effectively than a deep pot: the wider surface area s moisture more easily.
Stirring occasionally, let the sauce until it is reduced and thickened, about 30 minutes.