Preheat oven 415 degrees Fahrenheit (convection roast preferable).

On a rimmed baking sheet, toss the cherry tomatoes, shallots, and garlic with the balsamic vinegar, olive oil, and kosher salt. Spread everything out evenly so the vegetables aren’t crowded.

Roast for 25 minutes, or until the cherry tomatoes have popped, their skins have begun to separate from their flesh, the shallots have browned, and the garlic is soft.

Remove the pan from the oven and allow the vegetables to cool completely.

Remove the garlic and set aside.

Spoon the cherry tomatoes and shallots into the pitcher of a high-speed blender. It’s okay to leave some of the juice on the tray; we want the sauce to blend up thick.

Remove the garlic from their skins and add the garlic into the blender.

Add the fresh basil leaves and the sugar to the blender.

Blend on high until the sauce is completely combined and smooth.

Pour into jars. This sauce can keep five days in the fridge, or freeze for future use.