1.Heat oil in a large heavy-based saucepan over moderate heat. Cook beef, in batches, for 3-4 minutes or until seared. Transfer to a heatproof plate.
2.Add onion and a pinch of salt to pan; cook and stir for 15-20 minutes or until onion is golden brown. Return beef to pan. Add garlic and ginger; cook and stir for 30 seconds or until fragrant. Stir in spices; cook for 30 seconds or until fragrant.
3.Stir in 3 cups water and green chilli; bring to the boil. Reduce heat. Simmer, partially covered, for 1 hour. Add vinegar and sugar; simmer, uncovered, for 30 minutes or until beef is very tender and sauce has thickened. Stir in coriander. Remove from heat.
4.Serve curry with spinach, rice and lime wedges.
For a really good curry, cook onion well. Make sure it’s browned before continuing the recipe. Try pork instead of beef; cooking time may vary.