Prep the noodles. If using frozen or vacuum-packed udon, loosen them per package directions (quick boil or warm water rinse). Drain well and set aside. Fresh udon can go in at the end as-is if they’re already soft.

Slice the chicken. Cut thighs into thin strips, about 1/2 inch wide. Pat dry and season with a pinch of salt and pepper. Dry chicken browns better and avoids steaming.

Make the sauce. In a small bowl, whisk soy sauce, honey (or brown sugar), rice vinegar, oyster sauce (if using), and sesame oil. If you like a slightly thicker glaze, dissolve 1 tsp cornstarch in 2 tbsp cold water and add it to the sauce mix.

Heat the pan. Set a large skillet or wok over medium-high heat. Add 1 tbsp neutral oil and heat until shimmering.

Brown the chicken. Add chicken in a single layer. Don’t crowd the pan; work in batches if needed. Sear 3–4 minutes per side until browned and nearly cooked through. Transfer to a plate.

Sauté aromatics. Add another drizzle of oil if the pan looks dry. Stir in garlic, ginger, and the white parts of the scallions. Cook 30–45 seconds until fragrant, stirring so they don’t burn.

Cook the vegetables. Add firmer veggies first (broccoli, carrots, mushrooms) and stir-fry 2–3 minutes. Add tender ones (snap peas, peppers, spinach) and cook 1–2 minutes more. Keep them crisp-tender.

Combine chicken and sauce. Return the chicken and any juices to the pan. Pour in the sauce, and add 2–3 tbsp chicken stock or water to help it coat evenly. Toss and simmer 1–2 minutes until glossy.

Add noodles. Add the udon and gently toss with tongs, letting the noodles soak up the sauce. If the pan seems dry, splash in a bit more water or stock. Taste and adjust sweetness or saltiness as needed.

Finish and serve. Turn off the heat. Sprinkle with scallion greens and toasted sesame seeds. Add red pepper flakes or a few drops of chili oil if you like heat, and a light squeeze of lime for brightness. Serve hot.