Pad Thai Sauce

If using block tamarind: break off 60 g and soak in 120 ml of warm (not boiling) water for 15 minutes. Work the softened block with your fingers, squeezing and pressing until all the pulp dissolves into the water. Pour the mixture through a fine sieve, pressing hard on the solids to extract all the liquid. Discard the fibres and seeds. You need a thick, dark-brown liquid, about 3 tablespoons of concentrated paste per portion of sauce. If using tamarind concentrate from a jar, thin with a little water to a pourable consistency.

Combine the tamarind liquid, palm sugar, fish sauce, oyster sauce, and dark soy sauce in a small saucepan. Set over low-medium heat and stir continuously until the palm sugar dissolves completely — palm sugar lumps are denser than white sugar and need gentle heat and patience. Once dissolved, raise heat slightly and bring to a very gentle simmer for 2–3 minutes. The sauce will darken slightly and thicken a little as moisture evaporates. Remove from heat.

Taste the sauce critically on a clean spoon — pad thai sauce should hit sour first, then sweet, then salty, with a savoury undertow. Adjust: too sour → add more palm sugar in small amounts; too sweet → add more fish sauce (not tamarind, which would change the body); flat → add more fish sauce. The sauce should taste noticeably stronger than you want the finished dish, because it will be diluted slightly by noodle water and wok steam during cooking. Store in a jar at room temperature for up to 1 week, or refrigerate for 1 month.