Season lamb with salt and pepper. Heat oil and sauté lamb. Remove the lamb and set aside. Add chopped onion to skillet and sauté until lightly brown. Add fresh chopped tomato and garlic; sauté until tomatoes are soft (about 5-7 minutes). Then add fresh ginger, cilantro and the following spices:Vindaloo curry, cumin, black pepper, salt, chili flakes, turmeric powder, and paprika. Add tomato paste and mix all ingredients well. Next, add tamarind and water; mix well. Lower the heat and add the sautéed lamb. Cook for about 2 hours stirring about every 20 minutes to prevent burning.