Slow-Cooker Mulligatawny Soup

This soup is the result of British colonizers’ encounters with rasam, a souplike dish from Tamil Nadu, a region in southern India, that’s often made with lentils. “Milagu tannir,” or pepper water, evolved into mulligatawny when the British made it thick, chunky and meaty. In her book “From Curries to Kabobs,” the author Madhur Jaffrey wrote that mulligatawny was “an essential part of my childhood,” as she ate it at the homes of Anglo-Indian friends and in hotels on vacation. Mulligatawny now bears no resemblance to rasam and has many variations; it is a dish that was invented and modified for colonizers’ palates, and thus it has few rules. Ms. Jaffrey noted that “some curry powder has to be included for a true East-West flavor,” as curry powder is more British than Indian. This slow-cooker version is thickened with masoor dal and coconut cream, and enriched with chicken thighs and tart apple.