How to Make It
Heat the olive oil in a small saucepan. Add the tomatoes and garlic and cook over moderate heat, stirring occasionally, until reduced to 1/3 cup, about 20 minutes. Transfer to a bowl and let cool to room temperature.
In a food processor, pulse the tomatoes, butter, pepper, and salt until blended. Scrape into a bowl; stir in the basil.
In a large pot, steam the corn until just tender, about 3 minutes. Transfer to a platter and serve with the butter.