Preheat oven to 200°C. Line a baking tray. Make sure you have a clean tea towel, a pestle and mortar and a wok.
Roast the jackfruit: drain and rinse the jackfruit, then pat dry with the clean tea towel. Spread out on the lined baking tray and roast in the hot oven for 20 minutes. Use two forks to pull apart and shred the jackfruit.
Meanwhile, prepare the remaining ingredients: trim the lemongrass stalk, strip the bark and slice finely. Peel and finely grate the garlic and ginger. Finely slice the chillies. Pick the coriander leaves and finely slice the stems. Pick the mint leaves. Break the peanuts up in the pestle and mortar. Cut away the stems of the lettuce, pull apart the larger leaves and rinse under cold water. Halve the limes for the dressing, peel the shallot, cut it in half and finely slice it lengthways.
Cook the larb: warm the oil in the wok over a medium-high heat. Add the jackfruit and stir for three to four minutes. Add the lemongrass, garlic, ginger, two of the chillies and the coriander stems. Stir for two minutes. Turn the heat down to very low to keep warm, stirring occasionally to make sure it doesn’t catch.
Make the dressing: squeeze the lime juice into a bowl. Add the sliced shallot and squash it slightly to break it down a little. Add the soy sauce and sweet chilli and stir to combine.
Serve: spoon the jackfruit mixture into the lettuce leaves, drizzle over the dressing, garnish with the fresh coriander, mint leaves, broken peanuts and a few slices of chilli if you like it extra kicky! Serve immediately.