1 pint cherry or grape tomatoes (about 2 cups)
1 tablespoon fresh thyme leaves
1/2 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
2 sticks (8 ounces) unsalted butter, at room temperature
Arrange an oven rack about 3 to 4 inches from the broiler element and heat the oven to broil. Place the tomatoes on a rimmed baking sheet and broil until the skins begin to brown and the tomatoes start releasing their juice, 6 to 8 minutes. Let the tomatoes cool to room temperature.
Combine the broiled tomatoes, thyme, salt, and pepper in a food processor fitted with the blade attachment. Pulse about 10 times, until the tomatoes are finely chopped. Cut the butter into 1-inch cubes and add it to the food processor. Process until the butter is completely mixed in with the tomato mixture, about 30 seconds, scraping down the sides of the bowl as needed for even blending.
The tomato butter can be used immediately or placed in the refrigerator for a couple of hours to firm up first.