Processed Rice Flour - 1 cup
Water - 1 1/2 to 2 cups
Karamani (cow peas) - 1/2 cup
Powdered Jaggery - 2 cups
Grated Coconut - 1 cup
Cardamom Powder - a pinch
Dry roast the rice flour till it becomes slightly red in colour. Soak Karamani (cow peas) for about 6 to 8 hours. If the nonbu is to be done in the morning, then soak the Karamani over night. If it is in the evening or night, it can be soaked in the morning. Pressure cook it for about 3 whistles. Add less water so that it does not get over cooked.
Boil the water, remove 1/2 cup of boiled water. In the remaining water add jaggery. When it boils remove and strain. Keep it in flame again and when it comes to a boil add the karamani and coconut. In a minute or two add the roasted flour and whisk it thoroughly so that no lumps are formed. Add cardamom powder and mix it thoroughly. When everything blends well and forms a nice semi solid flour, remove from fire.
Knead well when cool and if the water is insufficient, add the remaining water and blend thoroughly. Make them into balls and flatten them in idly plates and pressure cook them without whistle.(Mark a hole in the middle while flattening them in the idly plates).