Bánh Mì Nấm

At Bánh Mì Chay Vĩnh Viễn, on Vĩnh Viễn street in the city's District 10, the mushroom arrives twice before the baguette is closed. A knife drags the shop's own mushroom pâté across the cut loaf in a pale brown, savory layer, and the sautéed mushrooms go over it, still warm, with the cool pickles piled on top. The pâté is creamy and smells of toasted garlic and soy, and it spreads the way a liver pâté does, thick enough to hold a smear of mayonnaise without sliding. Customers can buy the pâté by the container to take home, which makes the counter half sandwich stall and half pantry. The same baguette that holds the warm filling stays crisp at the ends, so the first bite goes through a thin shell and lands in damp, salty softness.

Mushrooms are mostly water, and the cook's whole job is to drive it out. A wide pan gets hot, the mushrooms go in torn rather than sliced, and they sit until the liquid hisses off and the edges turn brown and a little chewy. Oyster mushrooms tear into long strands that pull apart between the teeth like shredded pork, while a meatier cap gives a firmer bite. Garlic, soy sauce, pepper and a pinch of sugar go in at the end, so the seasoning clings instead of pooling. Filling that is pale and wet soaks the crumb within a minute and leaves a sandwich that tastes of damp bread, whereas a dry, caramelized one crackles faintly when it hits the pan and stays put in the loaf.

The sandwich belongs to chay, the Buddhist-influenced vegetarian cooking that crowds Vietnamese markets and street corners on the new-moon and full-moon days of each lunar month. On those days a shop like this one fills with people who want a quick lunch with no meat in it, and the sandwich has to carry what the meat usually carries. The fat comes from the pâté and the mayonnaise, the body from the mushrooms, and the sharpness from đồ chua, the pickled carrot and daikon. A classic meat bánh mì spreads liver pâté, and here the mushroom pâté sits in the same place on the loaf with a clean, earthy flavor of its own.

The rest of the build is quick. Cucumber spears add a cold, watery crunch, cilantro adds a green bite, and sliced chilli lights up the back of the mouth after the pickles have cut through the richness. The sandwich is handed over in a plastic bag or a twist of paper, warm in the middle and cool at both ends, and it costs under one US dollar. People eat it standing at the curb or riding home, and the pâté soaks slowly into the crumb, so the last third tastes more of mushroom than the first. Shops of this kind open early and close in the evening, which suits a sandwich that works at breakfast and again at dinner.

Because the filling is so simple, small choices show. A mushroom fried until it is dry and crumbly sheds into the bag, and a pâté with too much oil makes the heel of the loaf heavy and slick. Cooks who hold the line keep the stir-fry glossy but not wet, the pickles sharp, and the herb fresh, so each mouthful has a soft layer, a chewy layer and a crisp one. A little chilli oil or a splash of vegetarian fish sauce is common, and some stalls add a slice of fried tofu next to the mushrooms for another texture.

Origin and history

Vegetarian bánh mì shops sell tofu and mushroom fillings next to each other, and the mushroom version is a staple of the chay trade in Ho Chi Minh City, sold from shops that open at dawn and cook their fillings in the back. Who first filled a loaf with mushrooms goes unrecorded.

The pâté is the part a shop can own. A cook who grinds and cooks mushrooms into a spread is making the one thing the meat sandwich gets from a butcher, and doing it in a pot behind the counter. The sandwich then becomes a house product, and regulars come for that spread as much as for the filling.

The clearest dated picture of it is from March 2023, when the counter at 203 Vĩnh Viễn in Vườn Lài opened at 6:30 in the morning and ran until 7:30 in the evening, selling its mushroom bánh mì for under a dollar and its pâté by the container for cooking at home.