Peel the sweet potatoes and grate them coarsely using a box grater. Use a clean towel to squeeze out excess moisture, which helps the fritters crisp up nicely.
Transfer the grated sweet potato to a large mixing bowl. Add the all-purpose flour, beaten egg, finely chopped onion, cumin, and a pinch of salt and pepper. Mix everything together until well combined and the mixture holds together but remains slightly sticky.
Place a frying pan or skillet over medium heat and add about 1/4 inch of neutral oil. Allow the oil to heat until it shimmers and a small piece of batter sizzles and bubbles upon contact.
Scoop about 2 tablespoons of batter and gently form it into a flat patty in your hand. Carefully place it in the hot oil, pressing lightly to flatten and shape. Repeat with remaining batter, leaving space between each fritter.
Cook the fritters for about 3-4 minutes on each side, until they are golden brown and crispy around the edges. Use a spatula to flip gently, listening for a satisfying crackle as they fry.
Once cooked, transfer the fritters to a paper towel-lined plate to drain excess oil. Continue frying the remaining batter in batches, maintaining the oil temperature for even crispness.
Finish by squeezing a little lemon juice over the hot fritters to brighten their earthy sweetness. Serve immediately while still warm and crispy, perhaps with a side of your favorite dipping sauce.
