Salt beef: Toss beef in salt.

Check spiciness of kashmiri chilli powder and adjust if desired. See Spiciness Note below.

Curry Paste: Place Curry Paste ingredients in a Nutribullet or small food processor with 1 cup of the water. Blitz until smooth. Pour over beef. Pour remaining 1 cup water into Nutribullet, shake (to clean out remaining curry paste), then pour/scrape over beef.

Marinate beef: Mix beef in curry paste, cover, then marinate 2 hours. (Note: marinade is fairly thin - the water cooks down during slow cooking.)

Preheat oven to 190°C/375°F (170°C fan).

Curry sauce: Melt ghee over medium high. Cook onion, ginger and garlic until they become translucent - about 3 minutes.

Mustard seeds: Add black mustard seeds then cook until onion is tinged with gold. Stir in tomato paste, cook 1 minute.

Puree sauce: Add beef stock, stir. Transfer into a jug then use a stick blender to puree until smooth. Pour back into the pot.

Add beef: Add beef and curry leaves, stir then bring to boil.

Slow cook: Cover with a lid, then place in the oven for 2 hours or until beef is fall apart tender and the sauce has darkened in colour and thickened. (See Note 7 if sauce hasn't reduced enough).

Serve: Garnish with coriander, then serve over basmati rice with a side of naan!