I find lamb easy to be honest.In fact I find lamb easier than chicken! I bought 2 packs of diced lamb from Asda last week. All I do is pour about half a cup of oil into a pan, add some G&G paste, a couple of black cardamums (optional), half a dozen bay leaves, 4 or 5 cloves, 8 - 10 green cardamums, a nice piece of cassia bark (or a cinnamon stick), teaspoon of curry leaves (optional), 2 tsp salt and 2 tsp spice mix. Then I turn the heat up to medium until everything is sizzling well. Fill the kettle up full, tip the meat into the saucepan, whack the heat up to high, stir and brown the meat in the oil, pour the boiling water from the kettle to cover the meat well, and simmer for 90 minutes. Sometimes a scum forms on the top. Just ignore it. It will have disappeared before the time is up anyway.I do sometimes substitute the cassia for star anise.
Chicken on the other hand is far more hit and miss IMO.