Make the tamarind stock: dissolve the Tamarind Pulp in about 4 cups of warm Water, massage to release the pulp, then strain through a sieve to collect the sour tamarind juice; set aside.
Heat 1–2 tablespoons of Neutral Cooking Oil in a large pot over medium heat and gently sauté minced Garlic, thinly sliced Shallot and sliced Bird's Eye Chili until fragrant and slightly softened, about 1–2 minutes.
Pour the tamarind water into the pot, bring to a gentle simmer, and add bite-sized pieces of Pineapple and the sliced Taro Stem; simmer for 5–7 minutes so the flavors meld and the taro stem begins to soften.
Carefully add the Catfish Steaks to the simmering broth, lower the heat to maintain a gentle poach, and cook until the fish is just opaque and cooked through, about 6–8 minutes depending on thickness.
Add the Okra, halved or whole depending on size, diced Tomato and a handful of Bean Sprouts; simmer for another 2–3 minutes so the vegetables stay vibrant and slightly crisp.
Season the soup to taste with Fish Sauce, Sugar and a pinch of Salt, adjusting the balance of sour, salty and sweet until it sings — start with 1–2 tablespoons fish sauce and 1 teaspoon sugar and tweak from there.
Turn off the heat and stir in torn Rice Paddy Herb, chopped Sawtooth Coriander and sliced Scallion; finish with a squeeze of fresh Lime to brighten everything.
Serve the Canh Chua hot with steamed rice on the side, and extra lime or fish sauce at the table for individual adjustment.
