If you are using store-bought idiyappam, simply steam them according to the package instructions.
If you are making them fresh, prepare the idiyappam using rice flour, water, and a pinch of salt. Press the dough into idiyappam moulds and steam them.
Heat oil in a pan add mustard seeds, and let them splutter. Add urad dal and chana dal with some cashew nuts and sauté until they turn golden.
Add the slit green chillies, chopped ginger, curry leaves, and a pinch of asafoetida. Lower the heat and add turmeric powder, stir quickly, and immediately turn off the heat. Squeeze the juice of one lemon into the pan. Mix well.
Add the steamed idiyappam to the lemon mixture in the pan. Gently toss to ensure the idiyappam is well coated with the lemon mixture.
Garnish with freshly chopped coriander leaves. Serve the lemon idiyappam hot with coconut chutney or enjoy it on its own.