1. soak 1 cup Urid dal for 2 hours
2. wash it
3. blend with ~1/2 cup water to produce a thick batter
4. keep the dough in the fridge until needed
5. in another bowl, add
   • 1/2 cup plain flour (maida)
   • 1/4 cup semolina (rawa)
   • 1 spoon salt
6. mix with 3/4 cup water until no lumps
7. mix this mixture into the dough thoroughly
8. fry the polos

Goes well with Coriander Coconut Chutney