Soak the split peas overnight in cold water to cover. Drain thoroughly. Put through the fine blade of a food mill with the onion and garlic, or reduce to a purée in an electric blender. Season highly with salt and pepper. Beat with a wooden spoon until light and fluffy, or use an electric beater.
Heat the oil in a deep fryer or saucepan (570°F on a frying thermometer). Form the mixture,