Pomodoro

Quick Summary: This classic Italian sauce achieves a rich, velvety flavor with just three simple ingredients: tomatoes, butter, and an onion.
Source: Marcella Hazan

>> servings: 2
Crush the @whole peeled tomatoes{800%g} with a #food mill{}, #food processor{}, or #blender{} until smooth.  
-- If you want a more rustic sauce, leave the tomatoes whole or chunky, and let them break down naturally during the cooking.
 
Peel and cut the @onion{1} in half, but leave the root end attached so the onion doesn't fall apart during cooking.
 
Add the tomatoes, @butter{70%g}, peeled onion halves, and a small pinch of @salt{to taste} to a large #skillet{} over medium-low heat. 
-- A wider skillet reduces sauce more effectively than a deep pot: the wider surface area evaporates moisture more easily.
 
Stirring occasionally, let the sauce simmer until it is reduced and thickened, about ~{30%minutes}.
 
Turn off the heat and fish out the onion halves.
Taste the sauce and add salt as needed. Use immediately, or store the sauce in the fridge for about a week.