In a medium bowl, combine fat-free plain natural yoghurt, mango chutney, cornstarch, fresh mint, and lemon juice. Stir well until smooth, then refrigerate to chill.

Using a frying pan, spray low-calorie cooking spray and heat over medium-high. Add chopped onions and minced garlic. Cook for 5-7 minutes until golden brown. Set aside to cool.

In a large mixing bowl, combine lean lamb mince with salt, pepper, ground spices, and the cooled onion-garlic mix. Add the egg and mix until combined. Shape into 16 meatballs.

In the same frying pan, add more low-calorie spray. Once hot, sear koftas for 3-4 minutes on each side until golden brown. Remove and set aside.

Return to the pan, add more spray, then sauté onions, garlic, and ginger for 4-5 minutes. Add grated courgette and cook for another 3-4 minutes.

Stir in ground spices and cook for about 1 minute until fragrant.

Add tomato paste, sweetener, and chicken stock. Toss in cardamom pods and bay leaf, bring to a gentle boil, then simmer uncovered for 5 minutes.

Stir in mint yoghurt mixture and return koftas to the pan. Cover and simmer for an additional 12-15 minutes.

Taste and adjust seasoning with salt and pepper. Serve hot over basmati rice or with naan, garnished with extra mint if desired.