Lamb Khorma

Name: Lamb Khorma
Ingredients: 1 1/2 cups plain yogurt; 1 cup heavy cream; 1 tbsp minced garlic; 1 tsp ground cumin; 1 tsp ground fennel; 1/4 cup ghee (see tips, below) or canola oil; 12 oz cashew nuts; 2 1/2 lb boneless lamb leg, cut into 1 1/2 inch cubes; 2 tbsp ground coriander; 2 tbsp minced ginger root; 2 tsp ground cardamom; 3 cups small dice yellow onion; 6 Thai bird chiles, chopped, or to taste; Ground white pepper as needed; Salt as needed