For a hands-off approach to cooking Rogan Josh, try this slow cooker recipe. Using a food processor, blend together onions, garlic, ginger, and spices to create a flavorful paste. The paste is then combined with tender pieces of lamb, tomatoes, and yogurt in the slow cooker. Set it on low heat and let it cook for several hours until the meat is tender and the flavors have melded together. This slow cooker Rogan Josh is perfect for busy days when you want a delicious meal waiting for you at the end of the day.