Thompson's scholarship traces nam prik preparations to the very origins of the Thai culinary tradition — they predate the arrival of chilli, using long pepper and other indigenous heat sources. The arrival of chilli from the New World transformed the nam prik from a gentle aromatic relish to the intensely flavoured, heat-forward preparation of the modern table. Nam prik kapi, based on the fermented shrimp paste that was available to the earliest Thai cooks, may be the oldest surviving form of the preparation.
A pounded relish of roasted shrimp paste, fresh chillies, garlic, lime juice, palm sugar, and fish sauce — the archetypal nam prik of the central Thai kitchen, served as a dipping sauce for raw and blanched vegetables, fried fish, and plain boiled rice. Nam prik kapi is the preparation that Thompson identifies as the most fundamental expression of Thai seasoning philosophy in its simplest form: every element of the four-part balance (salt from shrimp paste and fish sauce, sour from lime, sweet from palm sugar, heat from fresh chillies) assembled in a single tablespoon.
**The roasting of gapi:** - Shrimp paste: 1 teaspoon. Wrapped in foil or moulded around the end of a wooden skewer, roasted directly over a gas flame for 1–2 minutes per side until fragrant — the raw, ammoniac edge of fresh gapi is replaced by a smoky, deeply savoury, complex note. [VERIFY: Thompson's specific roasting method — foil vs direct flame] - The roasting is essential: raw gapi produces a relish that smells and tastes harsh. Roasted gapi produces a relish of depth and complexity. **The preparation:** 1. Roast the shrimp paste. 2. Pound garlic and bird's eye chillies in the mortar to a coarse paste. 3. Add the roasted gapi. Pound to incorporate. 4. Season with fish sauce, lime juice, palm sugar. Adjust balance. 5. Taste: the relish should be simultaneously pungent (from the gapi), hot (from the chilli), sour (lime), sweet (palm sugar), salty (fish sauce and gapi). The gapi should be the dominant flavour note — present and complex, not overwhelming. Decisive moment: Roasting the gapi. The flavour transition from raw to roasted is significant and irreversible — roasted gapi cannot be unroasted. Under-roasted gapi (20 seconds over flame): still sharp and ammoniac. Correctly roasted (2 minutes per side): aromatic, smoky, complex. Always roast fully. Sensory tests: **Smell — the roasted gapi:** Raw gapi smells of fermented seafood — pungent, ammonia-forward, complex but aggressive. Correctly roasted gapi smells of deeply savoury, slightly smoky fermented shrimp — the ammonia note has been converted to a more complex, food-forward character. The smell test is the only reliable guide to correct roasting. **Taste:** Immediately pungent, then sour-bright from the lime, then the palm sugar's sweetness rounding the back palate, then the chilli's heat building. All four elements present; the gapi's depth providing the foundation for all of them.
*Thai Food* (2002); *Thai Street Food* (2010)