Step 1

Place the garlic, ginger and water in a blender or small food processor and blend into a smooth paste, scraping down the sides of the bowl as needed. Set aside.

Step 2

Preheat the oven to 225°F and adjust racks to the lower third of the oven. Warm the oil in a large Dutch oven or other heavy, oven-safe pot over high heat. Working in batches, brown the lamb pieces and set them aside in a bowl. Reduce heat to medium-high, add the onions to the pot and cook, stirring to scrape up any browned bits from the bottom, until onions are soft and translucent. Add the spices and salt and toast for 30 seconds to 1 minute, stirring frequently, until very fragrant. Add the garlic-ginger paste and cook for 1 to 2 minutes, stirring frequently, until most of the water in the paste has boiled away.

Step 3

Add the lamb pieces and their accumulated juices, the coconut milk and the tomatoes to the pan, and stir to combine. Cover, bring to a boil and place in oven. Bake for 1 to 1 1/2 hours, or until lamb is tender. Taste and adjust seasoning.

Step 4

Can be served immediately, but for best flavor and texture, refrigerate for 1 or 2 days before serving. Reheat gently on the stove or in the microwave and serve over rice or a roasted sweet potato.