To prepare the mint pesto, warm a small skillet over medium heat to toast the garlic cloves. Brown cloves on all sides for 2-3 minutes. Let the cloves cool, then peel them.
Place the nuts in the same skillet and toast them lightly over medium heat until lightly browned, about 5 minutes. In a food processor or blender, pulse the Mint Pesto ingredients until the mixture is combined and a desirable texture.
It only makes about 1/3 cup, but it is just enough for 4 burgers. Double the recipe if you want to freeze some for later.