Rinse 2 cups idli rice and 1 cup urad dal separately
Soak idli rice for 4 to 6 hours
Soak urad dal with 1 teaspoon fenugreek seeds for 4 to 6 hours
Drain the water from both
Grind urad dal and fenugreek seeds to a smooth, fluffy batter with little water
Grind idli rice to a slightly coarse batter with little water
Mix both batters in a large bowl
Add salt to taste
Mix well by hand
Cover and let it ferment for 8 to 12 hours or until doubled
Stir the fermented batter gently
Use the batter to make idlis