For the marinade, toast fennel, coriander and cardamom seeds in a dry frying pan over a medium heat until fragrant (about 4-5 minutes). Using a mortar and pestle, grind spices with a pinch of salt into a fine powder. Remove and reserve.
Pound the coriander and mint leaves with a pinch of salt in a mortar with a pestle until broken down. Add chilli, turmeric, garam masala, the freshly ground spices, lemon juice and yoghurt.
Coat the lamb cutlets in the masala mixture and marinate for about 2 hours.
For the pumpkin-almond curry, warm oil in a large saucepan or wok on a low heat and sauté mustard seeds and cardamom pod for a minute. Add cumin seeds, curry leaves, garlic and onion and sauté for 2 minutes.
Add pumpkin, 1 cup water, a pinch of salt, coconut cream, turmeric and almonds. Bring to a simmer and cook for about 15-20 minutes, until pumpkin is tender and sauce has slightly thickened (it should have the consistency of a soup).
In a frying pan, warm 1 tbsp oil over a medium heat. Cook cutlets in batches for about 3 minutes each side. Rest somewhere warm for 5 minutes, then serve with the curry.