Boil the noodles. Cook according to package directions until just tender. Reserve 1/4 cup of the starchy cooking water, then drain and set aside.

Prep your sauce base. In a small bowl, whisk soy sauce, brown sugar (or honey), rice vinegar, mirin, and water or broth. Stir in red pepper flakes or sriracha if you like a little heat.

Make the slurry. In a separate cup, mix cornstarch with water until smooth. Keep it nearby.

Sauté aromatics. Heat neutral oil in a large skillet over medium heat. Add garlic and ginger. Cook 30–45 seconds until fragrant, stirring so they don’t brown.

Add veggies or protein (optional). If using, add quick-cooking vegetables or pre-cooked protein now. Stir-fry 2–3 minutes. For raw chicken or shrimp, cook through before continuing.

Build the teriyaki sauce. Pour in your sauce base. Bring to a gentle simmer. Stir the cornstarch slurry, then pour it in and keep stirring. In 30–60 seconds, the sauce will thicken and turn glossy.

Toss in noodles. Add the cooked noodles and sesame oil. Toss to coat. If the sauce seems too thick, add a splash of the reserved noodle water to loosen it.

Finish and serve. Turn off the heat. Sprinkle green onions and sesame seeds. Taste and adjust with a pinch more sugar for sweetness, vinegar for brightness, or soy sauce for salt.