Preheat oven to 400°F. Remove the stems from all of the tomatoes. Remove the cores of the large tomatoes and cut them in half.

Place the tomatoes, garlic cloves, and shallots on a sheet pan. Drizzle with the olive oil and season with the oregano, red pepper flakes, and a few generous pinches of salt and pepper. Toss to combine. Arrange the tomatoes skin-side up. Sprinkle the thyme sprigs over the top.

Bake for about 40-45 minutes until the large tomatoes are soft and the small tomatoes have burst. Stir the basil into the tomatoes and roast another 5 minutes until the tomatoes are fragrant and have a few charred spots.

Remove the tomatoes from the oven and add the butter. Toss until it’s melted and glossy. Remove the thyme sprigs from the sauce and discard.

To blend the sauce: Transfer the tomato mixture to a blender. Blend until you reach your desired texture (I prefer a smoother sauce, but you can just pulse the blender a few times if you prefer a chunkier sauce).

To make the sauce by hand: Carefully pinch the skins off of the large roasted tomatoes (they should already be loose). You can leave the skins on the small tomatoes. Scoop out the seeds, if you prefer a smoother sauce. Transfer the tomato mixture to a large bowl and use a potato masher to smash the sauce. Be gentle, it may spray a bit!

Pour the sauce in a 24 ounce jar or container. Seal and refrigerate for up to 1 week or freeze for up to 3 months.