Name: Khai Yat Sai (ไข่ยัดไส้) — Thai Stuffed Omelette
Prep time: 10 min
Cook time: 15 min
Total time: 25 min
Yield: 1 large omelette
Cuisine: Thai
Ingredients: 150 g minced pork (หมูบด); 1 tbsp pounded garlic (กระเทียมโขลก); 30 g carrot, diced (แครอท); 2 tbsp oyster sauce (ซอสหอยนางรม); 2 tsp white soy (ซีอิ๊วขาว); 2 tsp sugar (น้ำตาลทราย); 1 tbsp ketchup (ซอสมะเขือเทศ); 60 g onion, diced (หอมใหญ่); 2 tomatoes, diced, seeds scooped (มะเขือเทศ); 1 spring onion (ต้นหอม); 3 eggs (ไข่ไก่); rice bran oil (น้ำมันรำข้าว)

The Omelette With A Secret

ไข่ยัดไส้ is the dish every Thai kid grew up with — a rice-plate staple that turns "what's left in the fridge" into the best lunch of the week. The name says the whole construction: ไข่ (egg) ยัด (stuffed) ไส้ (with a filling). A thin egg sheet, a savoury-sweet minced pork filling, folded shut like an envelope.

The filling is the flavour, and the flavour is the ketchup glaze. Phol's chef recipe fries pork with pounded garlic, seasons with oyster sauce, white soy, sugar and ketchup, then finishes on high heat with onion and tomato — with one detail that separates the careful version from the soggy one: the tomato seeds are scooped out first, so the filling reduces into a glaze instead of a puddle. The egg wrap goes around it while both are still warm, so the egg clings.

And because it's a leftovers dish by nature, the sources happily swap the pieces. Maggi's version adds white prawns to the pork. Pim's confession is the most honest account of the dish: her usual version takes ketchup, her no-ketchup version doesn't, and one day, with no ketchup in the fridge, she built the whole thing on Jazzii orange sauce instead — sweet-sour with a citrus edge — and documented it as a keeper. That's khai yat sai in one story: the recipe adapts, the envelope doesn't.

The Recipe (from Phol Food Mafia, Chef Thanakorn)

Thai	English	Amount
ไส้ (the filling)
หมูบด	Minced pork	150 g
กระเทียมโขลก	Garlic, pounded	1 tbsp
แครอทหั่นเต๋า	Carrot, diced	30 g
หอมใหญ่ / มะเขือเทศ	Onion / tomato, diced	60 g / 2
ต้นหอมซอย	Spring onion	1
ซอสหอยนางรม / ซีอิ๊วขาว	Oyster sauce / white soy	2 tbsp / 2 tsp
ซอสมะเขือเทศ / น้ำตาลทราย	Ketchup / sugar	1 tbsp / 2 tsp
ไข่ (the wrap)
ไข่ไก่	Eggs	3
น้ำมันรำข้าว	Rice bran oil	2 + 2 tbsp

Maggi's pork-and-prawn version: 100 g pork, 5 white prawns, seasoning sauce, oyster, ketchup, sugar, frozen mixed veg, 2 eggs. Pim's orange-sauce version: the same dish with Jazzii orange sauce in place of ketchup — her documented fridge improvisation.

The Method

The base. Garlic in hot oil; pork fried until almost cooked; carrot in.
The glaze. Oyster sauce, white soy, sugar, pepper and ketchup in; then high heat with the onion, seedless diced tomato and spring onion — fry until the sauce reduces and clings.
The rest. Filling off the heat to settle while the eggs are beaten.
The sheet. A thin, even omelette in a well-oiled pan.
The fold. Filling in the middle, envelope fold over it, seam down on the plate. Coriander and sliced spur chilli on top.

Where Thai Sources Disagree

The sauce. Ketchup is the standard (Phol, Maggi), but Pim's no-ketchup school exists, and her orange-sauce version is the documented third way. The ketchup glaze is the classic school-lunch flavour; the orange sauce is sweeter and sharper.

One protein or two. Pork alone (Phol, Pim) or pork with white prawns (Maggi). The prawn version is the special-occasion upgrade.

The vegetables. Fresh carrot, onion and tomato (Phol) or frozen mixed vegetables (Maggi's shortcut). Pim's approach is the dish's true north: whatever vegetables are left in the fridge.

Egg count. Two (Maggi) to four (Pim's bigger version) — three being the standard for one envelope. More eggs, thicker sheet; fewer, lighter.

Seeds or no seeds. Phol scoops the tomato seeds; the quicker recipes don't bother. It's the difference between a glaze that clings to the rice and a filling that waters it.

How Western Versions Get It Wrong

Calling it omurice. Similar silhouette, different filling — omurice is rice wrapped in egg with demi-glace; khai yat sai is a pork-and-vegetable stir-fry in ketchup glaze. The rice stays on the plate.
A thick western omelette. The egg must be a thin sheet that folds like paper — a thick fluffy omelette can't do the envelope fold.
Dry filling. The glaze matters — oyster sauce, ketchup and the tomato reduce into the sauce that makes the dish. A dry pork mince in egg is a different, sadder thing.
Tomato seeds in. Phol's detail — scoop them. The filling should glaze, not puddle.
Plain on the plate. It's served over or beside jasmine rice, with the coriander and sliced chilli on top. It's a rice-plate dish, not a standalone egg course.

UK Ingredient Notes

Everything is a supermarket item — pork mince, eggs, ketchup, oyster sauce (Thai or Chinese brand).
Rice bran oil can be any neutral oil; Maggi's version uses palm oil.
Seasoning sauce (Maggi's): Golden Mountain or Maggi seasoning from Thai grocers.
Jazzii orange sauce for Pim's variant: Thai grocers stock it — otherwise any sweet orange stir-fry sauce reads close.

Sources

This recipe is translated from the following Thai-language sources. Where they disagree, we've said so.

1. Phol Food Mafia — "Stuffed Omelette (ไข่ยัดไส้)" by Chef Thanakorn Phloisichomphu (the recipe used here) — pholfoodmafia.com

2. Maggi (Thailand) — "ไข่ยัดไส้" (pork-and-prawn version) — maggi.co.th

3. Pim's Kitchen (พิม) — "ไข่ยัดไส้หมูสับซอสส้ม" (the orange-sauce improvisation) — pim.in.th

Johnny Tiger

Johnny researches and translates Thai recipes from Thai-language sources — chefs, restaurants and home cooks in Thailand — and publishes them with their sources cited. No westernised shortcuts, no invented steps.