Sesame Noodles

Steps

1. Bring a large pot of water to a boil, unsalted: the soy sauce brings enough salt.
2. Meanwhile, finely chop the garlic. Slice the scallions, keeping the whites, chopped fine, apart from the greens, cut into thin rounds. Put the garlic and scallion whites in the bottom of a large heatproof bowl, the one you'll toss the noodles in.
3. Heat the neutral oil in a small saucepan over high heat until it shimmers and the first wisp of smoke appears, around 350°F (180°C). Pour it all at once over the garlic and scallion whites: it sizzles loudly, the garlic turns golden and loses its raw bite in a few seconds.
4. Stir the sesame paste in its jar (the oil always rises to the top), then add it to the bowl with the soy sauce, black vinegar, sugar, 1 tablespoon of the chili oil, and the toasted sesame oil. Stir: the sauce will be thick, almost grainy, and that's normal at this point.
5. Drop the noodles into the boiling water and cook for the time on the package, usually 3 to 5 minutes, separating them with chopsticks. They should be tender but still springy.
6. Just before they're done, scoop out 200 ml of the cooking water. Whisk 4 tablespoons of it into the sauce: it tightens at first, then relaxes into a smooth beige cream about as thick as heavy cream. Add another spoonful if it's still pasty.
7. Drain the noodles without rinsing, since their starch helps the sauce stick, and tip them straight into the bowl. Toss for 30 seconds with chopsticks, lifting, until every strand is coated. If the sauce turns tacky, add a bit more cooking water: it thickens as it cools.
8. Divide between two bowls, scatter with the scallion greens and sesame seeds, and drizzle with the rest of the chili oil. Eat right away, piping hot.