Grating: Grate plantains and onions with the coarse side of the grater.
Combining: Combine the grated plantain and onion. Mix in egg, salt, and chives.
Frying: Heat the oil over medium-high heat 350 °F [177 °C]. Scoop two tablespoons of the plantain mixture into the oil, fry 3 or 4 at a time so the oil doesn't get too cool. Once golden brown on one side, flip and fry until golden brown all over. Remove from the oil and rest on a paper towel to absorb excess oil. Serve warm.