Peel the plantains and cut into 1 inch thick slices. In a deep frying pan heat the oil and fry the plantains till golden brown. Flatten the plantains using a tostonera, or the bottom of a flat-bottomed glass bottle. Fry the plantains again for 30 seconds on each side.
(This part is optional) Mix the water, a pinch of salt and the mashed garlic. Stir and pour over the plantains.