In a large pot, bring the stock to a gentle boil. Add lemongrass, onion, ginger, and garlic. Simmer uncovered for 20 minutes to release deep aroma. Skim any foam from the surface for a clear broth.

Add fish sauce, soy sauce, rock sugar, tomato, tamarind paste, and chilli. Stir gently and let simmer for another 10 minutes. Adjust taste to balance savoury, sweet, and tangy notes. The broth should be bright yet comforting.

In a small bowl, whisk together fish sauce, lime juice, sugar, garlic, and chilli until sugar dissolves. Taste and adjust according to preference. This sauce will heighten the flavour of each bite later on.

Neatly organise the meat, seafood, tofu, vegetables, mushrooms, herbs, and noodles on separate plates. Presentation matters, as guests will cook directly from these platters.

Place the pot of simmering broth in the centre of the table over a portable burner. Keep the heat on low simmer so it remains gently bubbling throughout the meal.

Add a few pieces of meat or seafood at a time, followed by vegetables and tofu. Each ingredient cooks quickly, usually within a few minutes. Avoid overcrowding the pot to maintain flavour clarity.

Once cooked, retrieve ingredients using chopsticks or a slotted ladle. Dip into the prepared sauce before eating. Pair each bite with noodles or a spoonful of broth for the full experience.

As you eat, top up the pot occasionally with additional stock or hot water. Re-season with a splash of fish sauce if needed to keep the broth lively and aromatic.

Add fresh herbs towards the end of the meal for bursts of fragrance. A squeeze of lime brightens the flavours and balances the richness.

When the broth is nearly reduced, enjoy it as a light soup. Lẩu is best shared slowly, savouring both the food and the conversation.