- 3 pounds tomatoes
- Kosher salt
- 1/2 cup olive oil
- 4 garlic cloves, crushed
- 4 small sprigs rosemary
- 2 tablespoons unsalted butter
- Slice a thin round off the bottom of each tomato. Starting at cut end, grate tomatoes on the largest holes of a grater over a medium bowl until all that’s left is the flattened tomato skin and stem; discard. Season grated flesh with several generous pinches of salt.
- Heat oil in a large skillet over medium. Cook garlic, tossing occasionally, until golden brown, about 3 minutes. Add rosemary and cook, tossing, just until fragrant and starting to brown around edges, about 1 minute. Reduce heat to medium-low, add tomatoes, and bring to a simmer. Cook, stirring often, until mixture is slightly thickened, 5–10 minutes. Remove from heat, add butter, and stir until melted. Taste and season with more salt as needed.
- Sauce can be made 3 days ahead. Let cool; cover and chill.