Lamb Vindaloo

Ingredients

• 2 pounds lamb cubed
• 2 tablespoons coriander seeds
• 1 tablespoon cumin seeds
• 2 pounds tomatoes crushed
• 14 each garlic peeled and minced
• 6 each bay leaves
• 2 inch ginger root fresh, finely chopped
• 1/2 teaspoon black pepper ground
• 1/2 teaspoon cardamom seeds
• 1/2 teaspoon cinnamon
• 1/2 teaspoon cloves
• 1/2 teaspoon cayenne pepper
• 2 teaspoons mustard seeds ground
• 1 tablespoon turmeric
• 1 cup white wine vinegar
• 2 medium onions
• 2 medium potatoes
• 2 tablespoons butter