1. If using the dried shrimp, place in a small bowl with hot water to cover and soak for 30 minutes. Drain and pat dry with a paper towel.
2. Carefully smash the scallions with the side of a meat cleaver or a large chef's knife until mostly flattened. Pat dry with a paper towel to avoid any water droplets from causing the oil to splatter during stir-frying.
3. Heat the oil in a well-seasoned wok or a large skillet over medium-low. Add the scallion segments and let them fry slowly, so they turn yellow without burning. Stir occasionally so the segments brown evenly, 20 to 30 minutes. (This slowly rendered-out flavor is essential to this recipe - be patient and let the toasty flavor infuse the oil.) Meanwhile, combine dark and light soy sauces, sugar, and vinegar in a small bowl and set aside.
4. Reduce heat to low, add shrimp (if using), and cook for another 5 minutes. Increase the heat to medium and immediately pour the soy sauce mixture into the wok. The sauce will bubble finely and foam, then begin to caramelize (if it bubbles too much, your heat is too high). Stir to dissolve the sugar and let simmer for 2 to 3 minutes to thicken.
5. Turn off the heat, then add a pinch of white pepper, followed by the cooked noodles, and toss to combine. Divide the noodles between two bowls, making sure to scoop up the scallion segments, and serve.
Source: Hannaford fresh Magazine, July-August 2021