1 tsp garlic paste (blend lots of peeled garlic with a little vegetable oil, then freeze in ice cube trays)
1 tsp ginger paste (made as above)
2 green chillies
¼ tsp red chilli powder
½ tsp turmeric
½ tsp garam masala
juice ½ lime
100g unsalted butter
Mix the tandoori butter ingredients, plus some seasoning, in a small food processor or with a hand-held blender until smooth. Scrape onto cling film, then use the cling film to help you roll it into a cylinder. Twist the ends to seal in the butter and chill until firm. The butter will last in the fridge for a week, or in the freezer for up to 3 months.
Heat a heavy-based frying pan with a drizzle of oil until really hot. Season the fish, then place in the pan, skin-side down, and cook for 4-5 mins until crisp and almost cooked through. Carefully turn over, add a good tbsp of tandoori butter to the pan and spoon it over the fish as it melts. Serve straight away with the Crushed saffron potatoes and Green beans with coconut (recipes below), with any pan juices poured over.