Heat the oil in a nonstick pan over medium heat. Add the mutton cubes and cook for about 5 minutes or until browned all over. With a slotted spoon, transfer the meat to a bowl or plate.
Add the onion, garlic and ginger to the pan and cook, stirring frequently, for about 5 minutes or until the onions are tender. Add the curry powder and cauliflower, and stir to mix together.
Add the tomatoes and water and bring to a boil. Return the meat to the pan and reduce the heat to a simmer. Cover and cook for about 40 minutes or until the lamb and cauliflower are tender.
Add peas and coriander, and cook for 3 minutes or until the peas are hot. Stir in the curd and flour together in a small bowl. Stir this mixture into the sauce and cook over low heat, stirring, for about 2 minutes or until slightly thickened. Serve hot.