Ingredients

20 ripe plum tomatoes 

1/3 cup extra-virgin olive oil 

Pinch of crushed red pepper flakes 

Coarse salt and freshly ground black pepper 

Preparation

Bring a large pot of water to a boil; meanwhile, prepare an ice-water bath. With a paring knife, score an X on the bottoms of tomatoes. Working in batches, carefully lower tomatoes into boiling water; when skins begin to split (30 to 60 seconds), use a slotted spoon to transfer tomatoes to ice-water bath. When tomatoes are cool, remove skins (use a paring knife, if necessary), and discard. Halve tomatoes and remove seeds.

Heat olive oil in a large, wide saucepan. Add tomatoes and red pepper flakes; season with salt and pepper. Cook tomatoes until softened. Using a potato masher, crush tomatoes until they are very fine. Continue cooking until tomatoes are tender and sauce is thickened, 20 to 25 minutes more. Use immediately or let cool and refrigerate in an airtight container, up to 2 days, or frozen up to 2 months.