Stir the meat, onions and coriander in moderately hot oil in a large soup pot. Meanwhhile, pour boiling water over the lentils and let them swell for several minutes.
When meat and onions are thoroughly brown, drain the lentils and add them to the pot along with about 4 cups of fresh water. Reduce heat to simmer and toss in the vegetables. Cook until vegetables are tender--about an hour--adding salt and pepper near the end. You may also want to add more corriander.