Place olive oil and garlic in 9-inch microwave-proof pie plate.
Microwave on HIGH (100%% power) 45 seconds.
Drain pinto beans, reserving 1/3 cup of juices. Add beans and reserved juiced to garlic mixture in microwave-proof pie plate. Mash beans with potato masher until all are broken up. Stir in pepper.
Makes 2 cups.