1 lb. semi-fresh Chinese round or lo mein noodles (refrigerated; buy online or at Asian markets), or 1 lb. spaghetti
3 tbsp. dark soy sauce
2 tbsp. light soy sauce
2 tsp. granulated sugar
2 tsp. toasted sesame oil
1 tbsp. peanut or safflower oil, plus more for drizzling
1 lb. raw merguez lamb sausage, removed from casings
1 large carrot, peeled and very thinly sliced into planks or on a bias
2 leeks, white and light-green parts only, thinly sliced on the bias
4 baby bok choy, leafy tops shredded, bulbs thinly sliced
4 cloves garlic, chopped
1 piece ginger (2 inches), peeled and minced or grated
Scallions, sliced on the bias, for garnish
Bring a large pot of water to a boil. Salt water and cook noodles according to package directions. Drain.
Meanwhile, in a small bowl, whisk dark and light soy sauces, sugar, and sesame oil.
Heat a large cast-iron or nonstick pan over medium-high heat. Add a drizzle of oil to the pan, then crumble in the merguez. Cook, breaking up with a spoon, 4 to 5 minutes, until browned. Remove to a plate lined with paper towels. Pour off drippings from pan.
Still over medium-high heat, add 1 tbsp. peanut oil, 1 turn of the pan, and stir in the carrot, leeks, and sliced bulbs of bok choy. Cook, stirring, for 2 minutes. Add garlic and ginger; cook 1 minute. Add merguez, noodles, and sauce to the pan, tossing until combined. Garnish with sliced scallions.