Fresh oysters mixed with a thin batter of rice flour and egg, fried in a very hot, heavily oiled wok until the batter has formed a crisp, lacy, slightly charred crust around the oysters, served with a sweet sour sauce and fresh bean sprouts. Hoy tod is a preparation of Thai-Chinese origin that exists at the intersection of omelette and fritter — the batter provides a crisp scaffolding for the oysters while the egg scrambled around the edges of the preparation provides a soft, custardy counterpoint. The texture contrast — crisp, slightly chewy batter; soft, sweet oyster; custardy egg; crisp fresh bean sprout — is the preparation's entire achievement.
**The batter:** - Rice flour (tapioca flour is added by some versions): these flours produce a crispier, more translucent batter than wheat flour because their starch gelatinises at a higher temperature — the batter sets crispier and stays crispier longer. - Water: to the consistency of thin pancake batter. - Salt and a small amount of white pepper. **The preparation:** 1. Heat a large amount of oil (3–4 tablespoons) in the wok over very high heat until shimmering. 2. Mix the oysters briefly with the batter. 3. Pour the oyster-batter mixture into the centre of the hot oil. Do not stir. 4. Allow the batter to spread and begin to set from the edges — 60–90 seconds. 5. When the edges are crisp: crack 2 eggs directly over the centre. 6. Use a spatula to break the yolk and spread the egg around the edges of the batter circle. 7. Allow the egg to partially set. Flip sections of the batter-and-egg as they set — hoy tod is not flipped as a whole but in sections. 8. Continue until the batter is crisp and the egg is set with lacy, slightly charred edges. 9. The oysters inside should be just cooked — warm, soft, slightly translucent at the centre. Decisive moment: The oil temperature at the beginning. Hoy tod requires oil that is just short of smoking point — very hot, producing an immediate, aggressive sizzle when the batter hits the surface. Too cool: the batter soaks the oil, becomes greasy, and does not form a crisp crust. At correct temperature: the batter sets instantly at the surface, the lacy, crisp exterior forming before the interior can absorb the oil. Sensory tests: **Sound:** Immediate, aggressive sizzle when the batter hits the hot oil — the sound of the correct temperature. Soft, gentle sizzle = too cool. **Sight:** Lacy, irregular edges on the batter as it spreads in the hot oil — the batter thins at the edges and crisps into a lace-like fringe. This is correct. Smooth, even edges with no lacing = insufficient heat.
David Thompson, *Thai Food* (2002); *Thai Street Food* (2010)