Preparation With a cleaver or large knife halve lobster tails lengthwise. Discard shells and devein tails. Cut lobster into bite-size pieces. Discard coarse stems from spinach and chop enough spinach to measure 2 cups. Chop onion and mince garlic. Wearing protective gloves, mince serrano. Peel gingerroot and mince. With a mortar and pestle or in an electric coffee/spice grinder coarsely grind mustard seeds. In a 10- to 12-inch heavy skillet heat oil over moderate heat until hot but not smoking and cook onion, garlic, serrano, gingerroot, and mustard seeds, stirring, until onion begins to brown. Add coriander and cook, stirring, 1 minute. Stir in spinach and cook until it begins to wilt, about 30 seconds. Gradually add yogurt, stirring until combined well, and stir in lobster and salt. Simmer mixture gently until lobster is just cooked through, 5 to 6 minutes. Serve lobster and sauce over rice.
Preparation With a cleaver or large knife halve lobster tails lengthwise. Discard shells and devein tails. Cut lobster into bite-size pieces. Discard coarse stems from spinach and chop enough spinach to measure 2 cups. Chop onion and mince garlic. Wearing protective gloves, mince serrano. Peel gingerroot and mince. With a mortar and pestle or in an electric coffee/spice grinder coarsely grind mustard seeds. In a 10- to 12-inch heavy skillet heat oil over moderate heat until hot but not smoking and cook onion, garlic, serrano, gingerroot, and mustard seeds, stirring, until onion begins to brown. Add coriander and cook, stirring, 1 minute. Stir in spinach and cook until it begins to wilt, about 30 seconds. Gradually add yogurt, stirring until combined well, and stir in lobster and salt. Simmer mixture gently until lobster is just cooked through, 5 to 6 minutes. Serve lobster and sauce over rice.