Make the batter: To a mixing bowl, add wheat flour, rice flour, salt, soda, cumin, chopped onions, chilies, coriander leaves, ginger, curd and 3 tablespoons water. Mix together, adding more water if needed, and make a thick batter of dropping consistency.
Prep up to fry: Heat oil in a deep pan until medium hot. To test if it is hot enough, drop a tsp of batter. It should sizzle and rise to the surface without sinking.
Fry Mysore bonda: Scoop out 1 tablespoon of batter each time and leave into the hot oil. You can also use a steel fruit ball scoop. Fry them on a medium flame, stirring often, until crisp and golden.
Remove them to a cooling rack/ steel colander or kitchen papers. Fry the rest in batches. Serve mysore bonda hot with chutney or sambar.