Brown the lamb in 2 Tbsp of oil, 2 minutes on each side and set aside.Brown the onions, then add the chillies, garlic, ginger and curry powder. Sauté for 2 minutes.Add the lamb back into the pot and stir, season with salt and pepper.Add peeled tomatoes and 1 cup of water and bring to a boil for 5 minutes.Add butter beans and tomato paste, stir and allow to boil for 15 minutes.Place the lidded pot into the Wonderbag for 4-5 hours.Combine grated cucumber and yoghurt in a small bowl, and stir to combine.Serve curry over rice with yoghurt mixture and chopped bananas as toppings.Tip: Add carrots or potatoes to this curry for extra texture and flavour.