In a large bowl, combine the sweet potatoes, green onions, eggs, flour, salt and pepper. Mix thoroughly.
Pour enough vegetable oil into a large skillet to coat the bottom or use cooking spray. Place over medium heat just until a drop of water sizzles when it hits the pan. Add the sweet potato mixture to the hot oil by heaping spoonfuls about 1 in (2 cm) apart. Press each pancake lightly so that it sticks together. Cook about 2 minutes per side, turning over once, until brown and crisp on both sides and the sweet potatoes are tender right through. (Taste one to make sure they're done.) Remove to a paper-towel-lined baking sheet and place in a 300F (150C) oven to keep warm while you cook the rest of the pancakes.
Serve hot with sour cream, salsa or applesauce as an accompaniment.