Shanghai Scallion Oil Noodles (Cong You Ban Mian)

Combine the scallion pieces and neutral oil in a cold small saucepan or wok — starting in cold oil is critical. If you add scallions to already-hot oil they will fry hard and fast, browning too quickly before they have time to release their aromatics into the oil. Place over the lowest heat you can manage and cook for 30–40 minutes. The first 15 minutes will see very little activity — the oil will warm slowly and the scallions will begin to soften and wilt. From 15–25 minutes, the scallions will begin to shrink dramatically and you will see the first signs of browning at the green tips. From 25–40 minutes, the scallions will caramelize progressively from the tips down toward the white roots, going from golden to amber to a deep reddish-brown. The goal is that the scallions go almost fully dark — sweet-bitter, crispy shards — while the oil turns a deep golden-amber and smells like nothing else: sweet, savory, deeply caramelized allium. Stir every 5 minutes, more frequently in the last 10. When the scallion pieces are uniformly dark golden-brown and crispy, remove from heat.

In a large mixing bowl that will also serve as your tossing bowl for the noodles, combine the warm scallion oil (about 3 tablespoons per serving), light soy sauce, dark soy sauce, and sugar. Stir together with a spoon or chopsticks until the sugar is fully dissolved. The sauce will be a dark, glossy, highly aromatic liquid — the dark soy provides color and depth, the light soy provides salinity and brightness. Taste it: it should be very salty and intensely sweet-savory, because it will dilute dramatically when tossed with the starchy noodles. The ratio of scallion oil to soy sauce is important: too much oil and the noodles are greasy; too much soy and they are one-dimensionally salty. Adjust to your preference — more dark soy for a deeper color and molasses-sweet flavor, more light soy for a brighter, saltier result.

Cook the noodles in a large pot of vigorously boiling, lightly salted water until just done — fresh Shanghai noodles take 2–3 minutes, dried lo mein 4–5 minutes, thin spaghetti 7–8 minutes. Drain well, shaking the colander hard. Transfer immediately to the bowl of scallion sauce while the noodles are still very hot — the heat helps the sauce coat every strand. Toss vigorously and quickly with chopsticks or tongs, lifting and folding the noodles continuously for 60–90 seconds until every strand is evenly coated in the dark, glossy sauce. The hot noodles will absorb the soy quickly, so work fast. Taste and adjust: more soy for salt, more oil for richness, a few drops of scallion oil for aroma. Transfer to a serving plate or bowl and scatter a generous amount of the reserved crispy scallion pieces over the top. Serve immediately — scallion oil noodles are a dish of the moment, and the texture deteriorates rapidly.