Preheat the oven to 200°C, or 180°C fan.

Heat the vegetable oil in the large saucepan over medium heat.

Add the onion, red bell pepper, and green chilli to the saucepan.

Sauté the vegetables for 10 minutes until softened.

Stir the garlic, fresh ginger, garam masala, ground cumin, smoked paprika, ground coriander, and ground turmeric into the vegetables.

Cook the aromatics for 1 minute until fragrant.

Add the chicken thighs to the saucepan.

Cook the chicken for 8 minutes until browned and cooked through.

Pour the passata into the saucepan and season with salt and black pepper.

Simmer the curry for 10 minutes until the sauce thickens slightly.

Remove the saucepan from the heat and stir in 100 g of Greek yoghurt with the lemon juice.

Fold half of the fresh coriander through the curry.

Spoon the curry evenly into the 4 ramekins and let it cool slightly.

Combine the self-raising flour, remaining 200 g Greek yoghurt, and nigella seeds in the mixing bowl.

Mix the ingredients until a dough forms, then divide it into 4 equal portions.

Flatten each dough portion into a rough round using your hands.

Place one dough round over each ramekin and press the edges to seal.

Melt the unsalted butter and mix it with the remaining garlic and fresh coriander.

Brush most of the garlic butter over the naan tops, reserving a little for serving.

Bake the naan pies for 25 minutes until the tops are golden brown.

Brush the hot pies with the reserved garlic butter and serve.