Remove skin and bone from chicken thighs if using whole thighs

Cut each thigh into four pieces

In a bowl, combine natural yogurt, Kashmir chili powder, garam masala, turmeric, ground coriander, cumin, and sea salt

Add fresh lime zest, grated ginger, and grated garlic to the yogurt mixture

Mix until smooth

Add diced chicken and toss until every piece is coated

Cover and refrigerate for at least 30 minutes, preferably overnight

Blend onion, ginger, and garlic into a smooth paste with a splash of oil if needed

Heat ghee or oil in a heavy pan

Fry the onion, ginger, and garlic paste until it caramelizes slightly and smells sweet

Add green cardamom pods, ground cloves, ground coriander, cumin, garam masala, turmeric, Kashmir chili powder, and dried fenugreek leaves

Cook spices for 3-4 minutes until they sizzle and fill the kitchen with aroma

Stir in marinated chicken with all marinade

Cook until chicken starts to turn white on the outside

Add passata and chopped tomatoes, bring to boil while stirring

Lower to simmer and cook for about 30 minutes until chicken is tender and sauce thickens

Add cream and butter, stirring until melted

Add cashews and another sprinkle of dried fenugreek leaves

Finish with a drizzle of cream and freshly chopped coriander

For naan: Mix plain flour with dried yeast in a bowl

Add salt and baking powder

Add milk, a generous spoonful of yogurt, and a little oil

Bring together to a soft dough using a dough scraper or spoon

Knead for 8-10 minutes until smooth and springy

Shape into a tight ball and place in a bowl

Cover and leave to prove until doubled in size

Divide into four balls and rest for 10-15 minutes

Lightly oil work surface and rolling pin

Roll each ball to about 5mm thick and stretch into classic naan shape

Heat a frying pan until smoking hot

Cook naan for 2-3 minutes until it puffs up with bubbles and browns underneath

Flip and cook the other side the same way

Wrap cooked naan in a clean tea towel to keep warm and soft

Brush generously with garlic butter and scatter with coriander

Serve butter chicken hot with warm naan