In a medium bowl, combine the thinly sliced beef with 1 tablespoon of low-sodium soy sauce, 1 teaspoon of cornstarch, and the optional 1/2 teaspoon of baking soda. Toss well to coat. Let it sit for 10 minutes while you prepare other ingredients.

In another small bowl, whisk together the 1/2 cup soy sauce, honey (or brown sugar), rice vinegar, grated ginger, minced garlic, 1 tablespoon cornstarch, and 1/4 cup water until smooth and no lumps of cornstarch remain. Stir in the sesame oil. Set aside.

Heat 1 tablespoon of vegetable oil in a large wok or skillet over high heat until shimmering. Add the broccoli florets and carrots. Stir-fry for 2-3 minutes until slightly tender-crisp.

Add the sliced red bell pepper and snap peas to the wok. Continue to stir-fry for another 2-3 minutes until all vegetables are tender-crisp but still have a bite. Remove the vegetables from the wok and set aside on a plate.

Add the remaining 1 tablespoon of vegetable oil to the hot wok. Add the marinated beef in a single layer (you may need to do this in two batches if your wok is not large enough to avoid overcrowding). Sear for 1-2 minutes per side until browned, then break apart and stir-fry until just cooked through. Remove the beef from the wok and add it to the plate with the vegetables.

Pour the prepared teriyaki sauce into the hot wok. Bring to a simmer, stirring constantly, until the sauce thickens to your desired consistency (about 1-2 minutes).

Return the cooked beef and vegetables to the wok with the sauce. Toss everything together to ensure all ingredients are evenly coated in the rich teriyaki sauce.

Serve immediately over steamed rice or noodles, if desired. Garnish with sliced green onions and sesame seeds.