Step 1

Place brisket, stock, 1 lemongrass stalk, 1 kaffir lime leaf and 1 teaspoon salt in a large saucepan. Cover and simmer over medium-low heat, topping up with water if needed, for 4 hours or until the meat is tender. Cool slightly in the stock.

Step 2

Meanwhile, finely grate the remaining 2 lemongrass stalks and shred remaining kaffir lime leaf, then place in a pan along with rice vinegar, chilli, fish sauce, garlic and sugar. Bring to a simmer over medium heat, stirring to dissolve the sugar, then remove from heat.

Step 3

Shred the brisket, reserving the braising stock, and toss with half the dressing. Toss brisket, noodles, herbs, onion and cucumber together in a bowl with the remaining dressing and 1 cup cooled braising stock. Divide among bowls and serve.