Onion Uthappam Recipe I used readymade batter for the dosa. To make the batter at home, take rice : urad dhal in 3 : 1 ratio, soak overnight (or atleast 5-6 hours) in water separately, grind separately and then mix together, adding salt. This batter should be kept covered for another 5 hours or so before you can start making the dosa. Once the batter is ready, pour enough batter on a hot griddle and spread in a round, even shape. It should be thicker than the normal dosas. Then, lay finely chopped onions over the uthappam. Sprinkle some gingelly oil and turn to cook the other side. I normall add fresh finely chopped cilantro leaves and red chillies too, but didn’t get any this weekend and I was out of red chillies too. Do try the variation. The crunchy onion pieces that you come across while you eat is divine! Serve hot with coconut chutney and sambhar.