Bun cha, the Hanoi lunch that closes at two

Follow the smoke at half past eleven in the Hanoi old quarter. It leads to a clay brazier on the pavement, a cook turning pork patties with a hand fan going, and four plastic stools that fill within the minute. Bun cha is the city's lunch, and it keeps its own hours.

What arrives when you order bun cha?

An order of bun cha arrives as three separate things. A bowl of warm, pale dipping sauce with pork in it, a plate of cold white noodles, and a heap of herbs and lettuce. Assembling them is your job, and the kitchen assumes you know that.

The pork comes in two forms in the same bowl. Cha vien are minced patties, flattened by hand and charred at the edges; cha mieng are slices of belly, fatty and caramelised. The cook grills both over charcoal and drops them straight into the sauce, so the sauce tastes of smoke by the time it reaches you.

Why is the pork sitting in a bowl of liquid?

The liquid is nuoc cham, the diluted fish sauce that holds half of Vietnamese cooking together. Here it is the dish rather than a condiment: fish sauce cut with four or five times its volume of water, then sugar, rice vinegar, garlic and chilli, with slices of pickled kohlrabi and carrot floating in it.

Warm matters. A cold dipping bowl belongs to other dishes; this one comes off the heat so the pork fat stays liquid and the sauce keeps its smell. It is mild enough to eat by the spoonful, which the neat fish sauce it starts from is not. The fish sauce guide explains the dilution.

Each diner gets their own bowl. Nobody shares one, and the pickles in it are eaten as you go rather than left at the bottom.

How do you eat bun cha?

Lift a small tangle of noodles into the sauce bowl, add a torn leaf or two, and eat that mouthful with a piece of pork. Repeat for twenty minutes. That is the whole method, and getting it wrong mostly means treating the noodles as the main event instead of the vehicle.

Two habits mark a first-timer: pouring the sauce over the noodle plate, and eating all the pork first. Neither ruins anything, and neither is what the table around you is doing.

The herbs are not a garnish. Perilla and Vietnamese balm carry most of the freshness in a bowl otherwise made of pork and fish sauce. The herb guide names what else turns up on the plate.

Bun cha or bun bo Hue, if you only eat one?

Bun cha is the Hanoi lunch and bun bo Hue is the central breakfast, and they share a first word and nothing else. One is grilled pork in a bowl of warm dipping broth with noodles alongside; the other is a single hot bowl of lemongrass and chilli beef soup with round noodles in it.

Eat bun cha in Hanoi and bun bo Hue in Hue, which is also the order most trips meet them in. If the question is heat, bun bo Hue is the loud one and bun cha is mild enough for anybody.

Why does bun cha close at two?

Bun cha is lunch in Hanoi and the kitchens are built around one service. Cooks light the charcoal late in the morning and portion the pork for the day. When it runs out the shutter comes down, usually between one and two.

A place still selling bun cha at eight in the evening is serving visitors rather than the neighbourhood. It will not be bad, but the grill has been cold for hours and the patties were reheated.

Plan the day around it rather than hoping to stumble into it at dinner. The Hanoi things to do page puts the old quarter walk in the morning for the same reason.

What does a set cost in Hanoi?

A full set of noodles, pork and sauce runs 50,000 to 80,000 dong, which at roughly 26,000 dong to the US dollar is two to three dollars. That is a pavement price, paid in cash, at a place with plastic stools and no menu.

Adding nem cua be, the crab spring roll that Hanoi serves alongside, pushes the bill past 100,000 dong. Tourist-facing restaurants charge two or three times the stall price and grill nothing better, a gap the cheap eating guide covers across the whole country.

Carry small notes. A 500,000 note at a stall selling three-dollar lunches is a problem for the person serving you, as the money guide explains.

Should you order the crab spring roll?

Nem cua be is worth the extra 40,000 dong, and it is the standard companion order in Hanoi rather than an upsell. A square roll of crab, pork and mushroom, deep fried, cut into pieces and dropped into the same sauce bowl.

The crab roll is a northern speciality and specifically a Hai Phong one, from the port city about 100 km east, which is how it ended up on Hanoi menus. Order it with the bun cha rather than after it, since the fryer and the grill work together.

The spring roll guide sets out the rest of the family: which rolls are fried, which are fresh, and which name belongs to which region.

Is bun cha the same as bun thit nuong?

The two dishes share grilled pork, rice noodles and fish sauce, and assemble them in opposite ways. Bun cha is northern and wet: the pork sits in a bowl of warm sauce and the noodles come to it. Bun thit nuong is southern and dry: the pork sits on the noodles in one bowl and you pour the sauce over the top.

Ordering the northern dish in Ho Chi Minh City gets you a transplant. The cooks know it well enough and keep hours the north would not. Ordering the southern dish in Hanoi is the same trade in reverse.

Bun cha and bun thit nuong both belong to the family of charcoal dishes mapped in the grilled food guide. Neither is a soup, which is where the noodle soup guide draws its line.

Why does one Hanoi shop have a queue for a glass case?

Bun cha Huong Lien on Le Van Huu street sells the same lunch as its neighbours, plus one thing they do not have. Barack Obama and Anthony Bourdain ate at a table there in May 2016, and the restaurant keeps it under glass with the stools and the beer bottles.

The kitchen sells the meal they ate as a set, and it is fine. It is also a twenty-minute queue for a dish that a hundred other kitchens in the city grill to the same standard, without the glass.

Eat it if the story appeals, and eat the neighbourhood version on the other days. Hanoi has more bun cha kitchens than any visitor can work through in a week. The good ones announce themselves with smoke rather than with signage. The other Hanoi lunch worth planning a day around is bun dau mam tom.