If you’re in a city with an open mind, gua bao – moreish Taiwanese steamed bread rolls (chewy on the outside, light on the inside) – are usually fairly easy to find. Small and stuffed with delicious treats such as braised pork or fried chicken, they are the perfect example of “street food” – a rather popular concept nowadays, we hear, and a means for many would-be restauranteurs to perfect their craft before expanding.

This is a concept familiar to London’s Bao restaurant – considered by many critics and chefs to serve the best, er, bao outside of Taiwan. Founded on a Hackney street market in 2013 by Ms Erchen Chang, Mr Shing Tat Chung and Ms Wai Ting Chung (all, annoyingly, still in their late twenties and early thirties), it was snapped up by restaurateur Mr Karam Sethi – an almost mythical figure in the city’s food circles thanks to his flawless “casual fine dining” portfolio of Bubbledogs, Lyle’s, and Gymkhana. He brought Bao to the masses via a more permanent base in Soho’s foodie square mile (where, thankfully, people are used to queuing street-food style). On 7 July, Bao will open its third outpost in Fitzrovia, Windmill Street – where you may already find the start of a patient line of hungry customers.

Apart from their famous buns and xiao chi (small bites), what can we expect from the new 47-seater site? We asked the chefs in the Bao kitchen, who responded by very kindly giving us a recipe for one of their favourite creations: beef soup and rice.

• Rapeseed oil
• 500g beef bones
• 1 onion
• 1 carrot
• 1 tomato
• 1 bunch spring onion
• 1 knob of ginger
• 500ml water
• 1/2 cup of shao xin wine
• A pinch of black peppercorns
• 3 star anise
• 2 tablespoons chilli bean paste
• 3 tablespoons soy sauce

1. Take a stockpot, add a dash of rapeseed oil and on a high heat, brown the bones, vegetables and ginger for five minutes before pouring in the water, wine, peppercorns and star anise. Simmer for at least 3 hours.

2. Strain and discard the vegetables and bones. Take your remaining stock, bring back to the boil and reduce by one third. Season with chilli bean paste and soy sauce to taste.

3. When you are happy with the flavour, pass the mixture through a sieve again to remove any lasting pulp.

• 400g beef sirloin steak
• Sea salt for seasoning
• Rapeseed oil
• Enough steamed rice for 4-6 people
• Black truffle shavings (optional)
• Beef soup (above)

1. Heat a heavy-bottomed pan on a high heat. Season the steak with sea salt and with a dash of rapeseed oil, sear the meat in the pan on all sides. This should only take 3-5 minutes in total so the beef stays rare. Rest the meat for five minutes before slicing thinly.

2. Assemble the beef slices over each bowl of rice and shave truffle over the top.

3. At the table, pour the hot beef soup from a jug over each dish, making sure that each serving is generous so the rice is nice and soupy.