- Use stale or dried bread. Drier bread soaks up the custard better. Baguettes are great because you can cut it into thick small pieces, and really soak up the custard; and the crust adds another layer of texture. Challah bread is allegedly amazing too.
- Refresh the cooking oil / butter for every round of toasts. The overcooked bits would burn in the oil and make latter toasts taste bitter.
- The toast will create a lot of bubbles in the oil. When the bubble dies down, it means that side is cooked and it's time to flip.
- Cook wide noodle in salted water. The noodle should be on the softer side.
- Take the noodle out into a bowl. Add some black vinegar, then put a layer of crushed red pepper, salt, and minced garlic.
- Heat a little bit cooking oil till it smokes. Peanut oil is preferred.
- Quickly pour the oil evenly on the layer of spices. Stir well and serve.
That's the gist of it. You can also add vegetables on step 2: bean sprouts, leafy greens; add scallion or peanut crumbles; or use soy sauce for the salt. Sichuan pepper is amazing here too, though obviously not for everybody.
So long as there's enough spices in the layer, the oil temperature is high, and the vinegar is unsweetened black vinegar, this dish would be good. The best vinegar for this dish is called 老陈醋 (Mature Vinegar).