1. Rinse rice in cold water, and soak in cold water for at least 2 hours (can soak for up to 4 hours).

Prepare Biryani Masala

1. Heat oil in a large vessel over medium-high heat. Add sliced onions and sauté until golden brown, 5 to 10 minutes.
2. Transfer half of the browned onions to a paper towel lined plate and set aside. These will be used when the biryani is being layered.
3. Returning to the cooking onions, add ginger garlic paste and beef, and sauté until the beef has a good sear on it, about 3 to 5 minutes. Reduce heat and add tomatoes, cover, and cook until the beef is tender and the onions and tomatoes have cooked down into a thick paste, about 1½ to 2 hours. Add splashes of water and stir as necessary to help tenderize the meat and to prevent burning at the bottom of the pot.

4. While the beef is cooking, mix the following together in a bowl: yogurt, coriander powder, red chili powder, turmeric, paprika, black pepper, nutmeg, mace, salt, green cardamoms, cloves, black cardamoms, cinnamon, bay leaf, and star anise.

5. Once the beef is ready, add the prepared yogurt and spice mixture. Cook until the oil begins to separate from the gravy, about 10 to 15 minutes. Add potatoes and cook until they are semi-cooked through (they will continue cooking while steaming with the rice), about 10 to 15 minutes. Remove from heat and mix in cilantro, mint, lemon (or lime) juice, and green chili. Set aside.

Prepare Rice

1. Heat water (enough to boil rice in) and salt in a large vessel over medium-high heat. Once it comes to a boil, add soaked rice (drain before adding), and cook until about 75% cooked through. Drain and set aside.