Preheat the oven to 350 degrees. Prick the sweet potatoes on all sides with a fork, wrap in foil, and place in the oven. Roast for 1 hour, turning at least once.
When the sweet potatoes are cooked, place them in a bowl and cover with plastic wrap. Steam for about 10 minutes, then remove the plastic and peel the potatoes.
Place the flesh in a bowl and mash well. Allow to cool slightly, then mix in the egg, curry powder, and salt.
Add one tablespoon of flour at a time to stiffen the mixture to make sure the fritters hold together.
Heat the oil in a pan. Scoop 1/4 cup of the sweet potato mixture into the pan, and press into a disc about 2 inches thick. Do the same with the remaining mixture, working in batches. Cook about 3 minutes per side, or until golden brown. Remove to a plate lined with paper towel.
Serve hot.