Whisk ⅓ cup soy sauce, 2 Tbsp. sambal oelek, 2 Tbsp. unseasoned rice vinegar, 1 Tbsp. honey, and 1 Tbsp. sriracha in a small bowl to combine. Set sauce aside.
Remove dark green parts from 1 bunch scallions and thinly slice; set aside. Thinly slice white and pale green parts. Heat ¼ cup vegetable oil in a large wok or skillet over medium-high. Add white and pale green scallion parts, 4 garlic cloves, finely chopped, and one 1″ piece ginger, peeled, thinly sliced, and cook, stirring occasionally, until slightly softened, about 2 minutes. Add 1 red bell pepper, ribs and seeds removed, cut into strips, 1 green bell pepper, ribs and seeds removed, cut into strips, 1 onion, cut into 1″ pieces, and 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt; cook, stirring occasionally, until slightly softened and beginning to brown around the edges, about 4 minutes.
Meanwhile, cook 1 lb. fresh or frozen or 12 oz. dried wheat noodles (such as udon, ramen, or bucatini) in a medium pot of boiling water according to package directions (salt water if using bucatini). Drain noodles, reserving ½ cup cooking liquid.
Add noodles and reserved sauce to skillet. Cook, tossing and adding reserved cooking liquid as needed, until noodles are coated and glossy. Toss in three fourths of reserved dark green scallion parts.
Transfer noodles to a large shallow bowl; sprinkle with toasted sesame seeds and remaining dark green scallion parts.