1.Heat oil in a saucepan over low heat. Add onion; 2 minutes or until almost soft. Add cumin and coriander; cook and stir for 30 seconds or until fragrant; Add tomato; cook stirring occasionally, for 5 minutes or until reduced and thick. Add beans; stir to combine, Season,
2.Microwave pappadums, in batches, on High (100%) in 30-second bursts-until puffed and cooked.
3.To assemble, top each pappadum with lettuce, bean mixture cucumber, then coriander, Serve.
No microwave? Shallow-fry pappadums in vegetable oil, in batches, until puffed and golden. Transfer to paper towels. Cool.