Heat a wok and add half of the oil. Once the wok is fully heated, pour in the beaten eggs and cook. Use a spatula to break the eggs into medium-sized pieces. Remove from the wok and set aside.: The moment your pan starts to shimmer with heat you will smell a faint toasted scent from the oil, and that is your cue to pour in the beaten egg . Expect a quick sizzle as the eggs hit the surface, and you will see the edges set almost immediately into glossy curds. As you use a spatula to gently break the eggs into medium sized pieces, listen for a soft popping sound as pockets of steam escape, and look for custardy, not dry, curds. This partial cooking preserves tenderness and ensures the eggs can absorb sauce later. Why this step matters, I have found, is that pre cooking the eggs prevents them from overcooking when combined with the sauce. A common mistake here is leaving the eggs in the pan until they are fully firm; they should still be slightly underdone when you remove them, because they will finish cooking later and you want them to stay moist.
Combine all the sauce ingredients and stir until well mixed. In the same wok, add the remaining oil. Once the oil is heated, add the tofu and lightly pan-fry on both sides. Add the tomatoes and stir until softened, then pour in the sauce, stir to combine, and gently fold in the eggs.: As you whisk the ketchup, oyster sauce, chicken broth, sugar, white pepper, and sesame oil (reserve the sesame oil for finishing if you prefer) you will notice the mixture taking on a glossy sheen and uniform color. The aroma will shift from individual components to a single savory sweet scent, which signals the sauce is ready. Mixing first makes it easier to coat the ingredients evenly and prevents clumping of the ketchup. This step is important because adding an already emulsified sauce to the hot pan promotes even flavor distribution. A frequent oversight is adding ingredients separately into the pan which leads to uneven seasoning; pre mixing avoids that problem.
Give it a few quick stirs to ensure the eggs are well-coated with the sauce. Add the chopped scallions, then dish up and serve immediately.: When you add the second portion of oil and it warms, you will see delicate ripples and the surface will gleam. Gently lay the tofu pieces in the pan, and listen for a soft hiss as moisture meets heat. Allow each side to develop a light golden surface without moving them too much, this forms a pleasant contrast between a slightly drier exterior and a creamy interior. The resulting aroma is faintly nutty and toasty, which complements the sauce. Light pan frying firms the tofu just enough so it will hold its shape during later stirring. Be cautious of overhandling the tofu , since pressing or tossing too aggressively is the usual way it breaks apart prematurely.
Add the tomatoes and stir until softened, then pour in the sauce, stir to combine, and gently fold in the eggs: Adding the wedges of tomato after you have seared the tofu lets them kiss the pan briefly, releasing fragrant steam and sweet juice as they soften. You will see the sauce thin and take on a silky sheen when poured in, and it will begin to cling to the tofu and tomatoes. Gently folding in the reserved egg means coaxing the curds through the sauce so they pick up flavor without breaking up completely. The sound in the pan will be quieter now, a gentle simmer rather than a hard sizzle, and the visual cue is glossy sauce coating each piece. This technique matters because it preserves textures and creates a cohesive bite. A common error here is stirring too forcefully, which tears the eggs and turns the tofu into fragments, losing the pleasing contrasts.
Give it a few quick stirs to ensure the eggs are well coated with the sauce. Add the chopped scallions, then dish up and serve immediately: The final stirs are when the dish comes together, you will notice the sauce distributing and the aroma intensifying as heat helps the flavors meld. Adding the scallions at the end preserves their fresh green color and bright snap, and you will hear a faint hiss as they hit the warm sauce, releasing a lively scent. Serving immediately is important to retain the contrasting textures, because the tofu will continue to soften if left in the sauce for long. The why here is simple, serving right away ensures the balance of warm sauce, tender tofu , and fluffy egg . A common slip up is letting the dish sit in the pan too long which causes sogginess, so transfer to a warmed plate promptly.