For the plantain and potato röstis, fold a clean tea towel around the grated potato and squeeze to remove as much moisture as possible. Combine the potato, plantain and onion in a bowl.

Like potatoes, plantains are primarily a source of carbohydrates. In 3.5 ounces of vegetable bananas, there are as many as 32 grams of carbohydrates, more than in potatoes (approximately 17 grams).