Puree ground lamb in a food processor to a fine paste.

Combine pureed lamb with fennel powder, ginger powder, salt, cumin, and black cardamom powder and mix well.

Divide the meat mixture into 4 equal portions and form into large balls.

In a small pan, heat 1 1/2 cups of water with cinnamon stick, bay leaf, cloves, and salt.

Bring the water to a boil and gently add the meatballs.

Cook the meatballs uncovered on medium heat for approximately 20 minutes, or until they are cooked through and tender, turning them halfway through the cooking process.

Heat oil and ghee in a kadhai (Indian wok) or deep frying pan.

Add sliced onion to the hot oil and ghee, and sauté until the onion turns golden brown.

Remove the sautéed onions from the oil and allow them to cool slightly.

Grind the cooled sautéed onions into a fine paste using a little water.

Set the cooked onion paste aside.

Add minced garlic to the same oil in the kadhai and sauté on low heat for about 30 seconds.

In the kadhai, add well-beaten Greek yogurt and the remaining sauce ingredients: caraway seed, fennel powder, ginger powder, garam masala, dried mint, black cardamom powder, and green cardamom powder.

Maintain low heat and stir continuously until the mixture comes to a boil.

Incorporate the onion paste into the yogurt sauce, mixing well for about a minute.

Gently add the cooked meatballs along with any remaining water from boiling the meatballs to the sauce.

Reduce the heat to low, cover the kadhai, and let the mixture simmer for 20 minutes to allow the flavors to meld.

Serve the Gushtaba garnished with fresh mint leaves.