Step 1: Prepare the Teriyaki Sauce: In a small bowl, whisk together soy sauce, mirin (or rice vinegar), honey, sesame oil, garlic, and ginger. Set aside. If you want a thicker sauce, stir in cornstarch slurry.
Step 2: Cook the Salmon: Heat vegetable oil in a large skillet or wok over medium-high heat. Season salmon with salt and pepper. Sear salmon fillets 3–4 minutes per side until golden brown and just cooked through. Remove from skillet and set aside.
Step 3: Stir-Fry the Vegetables: In the same skillet, add a little more oil if needed. Add carrots and broccoli first, stir-fry for 2–3 minutes. Add bell peppers and snap peas, stir-fry another 2 minutes until vegetables are crisp-tender.
Step 4: Combine Everything: Add cooked noodles to the skillet with vegetables. Pour teriyaki sauce over noodles and vegetables, tossing to coat evenly. Gently add salmon fillets on top, spooning some sauce over the salmon. Simmer for 1–2 minutes to warm everything through and allow flavors to meld.