Begin by preparing the broth. In a large pot, bring the chicken or pork broth to a gentle boil over medium heat. Add the bruised lemongrass, kaffir lime leaves, minced garlic, onion, and tomatoes. Simmer for 10 minutes to infuse the broth with aromatic flavours. Skim off any foam that rises to the surface for a clearer broth.

Add the tamarind paste, fish sauce, sugar, and sliced chilies to the simmering broth. Taste and adjust seasoning, balance is key. Add more tamarind for tanginess or fish sauce for depth. Lower the heat to maintain a gentle simmer while you prepare the fillings.

Prepare the seafood. Rinse the shrimp, fish fillets, and squid rings under cold water and pat dry. Arrange them on a large platter along with the thinly sliced beef or pork. Keep this platter refrigerated until ready to cook.

Blanch the rice vermicelli noodles in boiling water for 2 minutes or until tender. Drain and rinse under cold water to prevent sticking. Arrange the noodles neatly in a serving bowl and set aside.

Wash and prepare the vegetables and mushrooms. Slice the mushrooms into bite sized pieces, and trim the greens into manageable lengths. Arrange these alongside the fresh herbs on a large serving tray.

Prepare the dipping sauce. In a small bowl, combine hoisin sauce, chili paste, and minced garlic. Mix well and adjust to taste by adding a splash of lime juice if desired. Provide individual dipping bowls for each diner.

Bring the hotpot experience to life. Transfer the prepared broth into a portable hotpot or table top cooker set at the centre of the dining table. Set the heat to a gentle simmer. Surround the hotpot with the platters of seafood, vegetables, noodles, and dipping sauces.

To serve, let diners add their preferred ingredients to the simmering broth, cooking them to their desired doneness. Encourage everyone to enjoy the dish with fresh herbs, lime wedges, and dipping sauce. For a complete experience, pair the meal with steamed rice or crusty bread.