In a saucepan over high heat, brown the onions in the oil until tender. Add the ginger, garlic and Curry Spice Mix. Cook for 1 minute. Add the tomatoes and continue cooking for a few minutes, stirring constantly, until it has the consistency of a thick paste
Add the meat and thoroughly coat with the sauce. Add the yogurt, water, tomato paste and potatoes. Season with salt. Bring to a boil.
Cover and simmer over low heat for about 1 hour and 15 minutes or until the meat and potatoes are tender.
Serve with naan bread. Delicious with Cilantro Chutney (see recipe).