Hyderabad Dum Biryani

Name: Hyderabad Dum Biryani
Ingredients: 10 black peppercorns; 6 whole cloves; 5 cardamom pods; 2 cinnamon sticks; 2 whole star anise pods; 0.5 teaspoon kala jeera (black cumin seeds); 1 bunch fresh cilantro leaves; 1 bunch fresh mint leaves; 1 cup plain yogurt; 2 teaspoons lemon juice; 2 teaspoons ginger-garlic paste; 2 teaspoons chile powder; 1 teaspoon biryani masala powder (such as Dunya®); 0.25 teaspoon ground turmeric; 1 pound chicken thighs; 3.5 cups water; 2.3333332538605 cups basmati rice; 4 bay leaves, divided; 0.5 cup warm milk; 1 pinch saffron threads; 0.25 cup ghee (clarified butter), divided; 2 onions, thinly sliced; 2 green chile peppers, chopped