How to Make It
In a small dry skillet, cook the garlic cloves over moderate heat, turning occasionally, until softened and blackened in spots, about 15 minutes. Let cool slightly. Peel and lightly crush the garlic.
Meanwhile, in a food processor, combine the cheeses and scallions; process until smooth. Add the garlic to the processor and puree. Add the arugula and pulse until finely chopped but not pureed. Season with salt and pepper.