In 4 qt casserole, heat oil over moderate heat until light haze forms above it. Add dal and stir for a minute or so, then drop in mustard seeds and when oil sputters, add onions. Stir constantly, fry 7-8 minutes, until onions are soft and golden brown.

Add hot chili and stirring constantly, pour in the farina in a slow, thin streem. Still stirring, fry for about 5 minutes, or until farina is slightly browned. Stirring well after each addition, add tomatoes, carrots, scallions, water and salt. Bring to a boil over high heat, reduce to lowest, cover tightly, cook 10 minutes until farina is thick and vegetables tender. Taste for seasoning.

To serve, pour the uppama into heated bowl and sprinkle with coriander and lemon juice.