Heat 1 tsp oil in 5 liter pan, add ⅓ of the meat and sear uniformly. Once lightly browned transfer to a bowl and keep aside. Repeat for the remaining meat & 2 tsp oil.
Add remaining 1 tsp oil to the pan and heat again, add onions and cook for 15 minutes, stirring occasionally. Add ginger & curry paste, cook for 1 minute stirring constantly.
Add tomato paste & cook for 1 minute, stirring. Return lamb to the pot and add water, bring to a boil over high heat and cook for 1.5 hrs at low heat.
Add potatoes, stir & bring to a boil. Reduce heat and cook for an additional 30 - 45 minutes at low heat, or until potatoes are soft. Skim fat and sprinkle with cilantro.
Serve with naan or spinach to the side.
