Quarter 1 onion and cut the 1-inch ginger piece into thick slices.

Combine beef, quartered onion, garlic cloves, ginger, whole coriander seeds, 1 teaspoon cumin seeds, fennel seeds, star anise, cinnamon stick, peppercorns, black cardamom, cloves, and button chillies in the stockpot.

Pour in 1.5 litres water and add 1 teaspoon salt.

Bring the stockpot to a boil over medium-high heat and simmer until the beef is fork-tender, about 60 minutes.

Strain the beef broth through a fine mesh strainer and reserve the cooked beef.

Discard the boiled aromatics and keep the strained broth warm for cooking the pulao.

Rinse basmati rice until the water runs mostly clear and soak it in water for 30 minutes.

Slice the remaining onion, halve the green chillies, slice the tomato thickly, and quarter the half-boiled potatoes if using.

Heat cooking oil in the wide pot over medium heat and fry the sliced onion until deep golden brown.

Add a small splash of strained beef broth to the golden onion to stop it browning further.

Add 2 teaspoons salt, crushed red chilli, 1 teaspoon cumin seeds, coriander powder, garam masala, and ginger garlic paste.

Sauté the spices and onion mixture until fragrant and the oil begins to separate, about 3 minutes.

Add the reserved beef and fry it in the masala for 5 to 10 minutes.

Stir in the quartered potatoes, if using, and cook for 2 minutes.

Add plain yoghurt and halved green chillies, then stir until the yoghurt coats the beef.

Cook the beef mixture until some yoghurt moisture evaporates and the masala thickens, about 5 minutes.

Drain the soaked basmati rice and gently stir it into the beef masala.

Pour in enough reserved beef broth to cover the rice by about 1 centimetre, adding water only if more liquid is needed.

Arrange thick tomato slices over the rice and taste the broth for salt.

Cook uncovered on high heat until the rice is half cooked and most surface liquid has absorbed, about 8 to 10 minutes.

Cover the wide pot tightly and cook on very low heat for 20 minutes to steam the pulao.

Rest the pulao covered for 10 minutes, then fluff the rice gently and serve hot.