You’ll need a good size saucepan with a heavy base and a good lid. This is a one-pot dish, so the pan needs to be easily big enough to hold all the ingredients.
The first task is to give batches of the cubed lamb a good browning all over. So, set your pan on a high heat and add the cooking oil. When it starts to shimmer — but before it gets to smoking — stir in the first batch of lamb. Drop the heat to medium-high and let the lamb sizzle away in that hot oil with a few turning stirs for about 5 minutes. You’re aiming to get a pretty even, dark browning all over. You want to do this in batches so that the lamb quickly browns in a single, evenly-spaced layer in the bottom of the pan. As each batch finishes browning, remove it with a slotted spoon and set it aside on a plate.
Lower the heat to medium and add the onions to the pan. You want to fry the onions so that they soften and start to pick up a little golden color. A sort of slow-ish stir frying will get you there in about 7 minutes or so on that medium heat. Good.
Now turn the heat to high and quickly stir in the chilies, garlic, ginger, cardamom pods, lime leaves, and bay leaves. You want to give the mix a pretty hot stir-frying for 2 minutes so that the garlic just starts to take on a bit of color. The moment that happens, drop the heat to medium, and stir in the cherry tomatoes, cayenne pepper, cumin, fennel seed, fenugreek, cilantro, turmeric, salt and black pepper. Give the pan a through stir so that everything gets well mixed together. Then stir in the potatoes, the can of chopped tomatoes and the water.
Keep the heat on medium until the pan begins to bubble, then add the browned cubes of lamb — and all the juices from the plate they were sitting on. Give the pan a good stir, drop the heat to low and cover the pan. You now want your bunny chow’s curry to slowly simmer for about an hour — just until the potatoes cook right through. Give the curry a couple of stirs as it simmers, and, once the potatoes are done, turn off the heat. Sauce done.
You’ll probably find the potatoes have absorbed a fair amount of salt, so check your sauce and maybe add more salt to your taste. Leave the pan covered while you prepare the loaves of bread.