Goan Lamb Vindaloo

Name: Goan Lamb Vindaloo
Ingredients: ½ cup mustard oil; ¼ cup red wine vinegar (or apple cider or malt vinegar); 2 tablespoons tamarind pulp (concentrate is fine); 1 teaspoon sea salt; 1/4 cup minced garlic; 1-2 tablespoons finely chopped ginger (depending on your taste); 2 serrano chiles, seeds and vein removed; 2 teaspoons ground cumin; 1 1/2 teaspoons ground coriander; 1/2 teaspoon turmeric powder; 1/4 teaspoon ground fenugreek; 1/4 teaspoon ground ginger powder; 3/4 teaspoon ground cinnamon; 1/4 teaspoon ground cloves; 1/2 teaspoon ground black pepper; 1/2 teaspoon ground cardamom; 1/2 teaspoon ground sumac; 1 teaspoon hot mustard powder; 2 teaspoons cayenne; 2 teaspoons paprika; 2 pounds lean lamb, cut into 1″ – 1½” cubes; 1/4 cup ghee; 2 cups minced onion; 6 tablespoons water, or more as needed; 2 teaspoons jaggery (or light brown sugar); 1 teaspoon whole cumin seeds; 2 cups Greek yogurt; 1/3 seedless cucumber, peeled and grated or finely chopped (about 1/2 cup); sea salt