Heat peanut oil (360 ml) in a wide pan; fry sliced onions (340 g) in batches (don't crowd) until crisp golden. Set aside.
Grind the whole biryani spices (cinnamon (1), black cardamom (1), green cardamom (5), cloves (5), bay leaf (1), shah jeera (1 tsp), black pepper (1/2 tsp)). Mix chicken (680 g) with yogurt (160 ml) (thick, not runny), ginger garlic paste (1 1/2 tbsp), salt (1 tsp), chili powder (1 tsp), turmeric (1/2 tsp), chili (1), ground spices and ⅓ of the fried onions (340 g). Marinate 3–5 hrs.
Rinse basmati (400 g) till clear, drain. Soak 70g of it 1 hr. Boil 540ml water in rice cooker with ¾ tsp salt (1 tsp), 1½ tbsp olive oil (2 tbsp) and rice whole spices (black cardamom (1), green cardamom (3), cloves (4), bay leaves (2), cinnamon (1/2)). Add remaining rice, cook 15–20 min just until water absorbed; immediately spread on a wide pan (don't over-steam).
In a 4–5L ovenproof pot spread the marinated chicken (680 g) (marinade not runny). Scatter cilantro (15 g), mint (2 tbsp), half the lemon juice (2 tbsp), ½ tbsp olive oil (2 tbsp), then most fried onions (340 g). Drain soaked rice well and spread over; top with all cooked rice, then remaining lemon juice (2 tbsp), saffron water (1 tsp), fried onions (340 g) and ghee (2 tbsp).
Cover with parchment then foil, seal lid tight. Bake at 175°C for 1 hr until steaming (or stovetop: medium-high 10–15 min then low 1 hr). Rest 5 min, gently mix, mound showing all rice colors, top with chicken, extra onions and herbs. Serve with raita.