Step 1In a small saucepan, combine the jalapeno, vinegar, salt, sugar and garlic. Stir over low heat until the sugar dissolves, about 2 minutes.
Step 2Bring to a boil over medium-high heat and cook for 5 minutes, or until the mixture thickens to a slightly syrupy consistency. Remove from heat and set aside to cool while making the fritters. (The sauce continues to thicken as it cools; it can be made a day ahead.)
Step 1In a bowl, sift together the rice flour, flour, baking powder, salt, coriander and cumin. Add the egg, lemon juice and water. Beat until smooth.
Step 2Add the corn, spring onions and cilantro, stirring until just combined.
Step 3In a large frying pan, pour in enough oil to generously cover the bottom. When the oil is hot but not smoking, spoon 2 tablespoons of batter for each fritter into the pan, about half an inch apart, immediately flattening each fritter slightly. Cook over medium-high heat for 2 to 3 minutes, until golden brown underneath, then turn and cook the other side for about 2 minutes. Use a splatter screen to cover the pan. Transfer to a platter lined with paper towels. Repeat with the remaining batter, adding more oil if necessary.
Step 4Serve immediately with the sweet chile sauce.