Heat 3 tablespoons butter and 1 tablespoon light olive oil in a large pot
Add the whole spices, cinnamon, bay leaf, star aniseed and black cardamom. Fry until fragrant
Add the curry leaf, chilli, thyme and onion. Fry until the onion is golden brown
Add the ginger/garlic paste and sauté for a minute
Add the masala, chilli powder, fennel, turmeric, cumin, coriander and garam masala. Mix well and fry the spices for a minute. Add a drop of water to prevent the spices from burning
Add the lamb pieces. Mix well and allow it to fry with the spices for 5 to 8 minutes
Add yogurt, tomatoes and mint
Season with salt. Cover and simmer on low heat for an hour to an hour and a half until lamb is soft and tender. Add some water if the curry is drying out. I didn't add any water to mine