Preheat your oven to 400°F (200°C) and roast the sweet potatoes until they’re soft and caramelized, about 45 minutes. Once cooled, peel and grate them finely into a large bowl; you should have about 2 cups of grated sweet potato.
Add the all-purpose flour, beaten egg, chopped herbs, and a pinch of salt and pepper to the grated sweet potatoes. Use a spoon or spatula to gently fold everything together until the mixture is combined and slightly sticky, but not too wet.
Heat about 1/4 inch of neutral oil in a frying pan over medium heat until it shimmers and there’s a slight sizzle when you flick in a tiny bit of batter.
Scoop about 2 tablespoons of batter and gently press them into a flat, round patty. Carefully place the patties into the hot oil, leaving space between each one to prevent sticking.
Cook the fritters for about 3–4 minutes on each side, until they’re deep golden brown and crispy around the edges. Use a spatula to flip them carefully once they’re nicely browned.
Transfer the cooked fritters to a paper towel-lined plate to drain excess oil. Continue frying the remaining batter in batches, maintaining the oil temperature.
Let the fritters rest for a couple of minutes, then serve them warm with a squeeze of lemon or a dollop of sour cream for extra flavor and contrast.
