Mix all hibachi glaze ingredients except toasted sesame oil in a small bowl. Prepare mustard sauce by whisking mayo, Dijon, soy sauce, and rice vinegar in another bowl. Set aside.

Heat a large skillet over medium-high heat with 1 tablespoon of neutral oil.

Add sliced carrots and cook for 2 minutes until crisp-tender.

Add onions, bell peppers, and mushrooms, cooking each for about 2 minutes.

Finish with zucchini for 2-3 minutes, season with soy sauce, salt, and pepper, then transfer to a plate.

In the same skillet, add another tablespoon of oil and raise the heat to high.

Add chicken thighs in a single layer, sear for 2-3 minutes undisturbed.

Flip and cook for another 2-3 minutes until mostly cooked through, then set aside.

Return chicken to the skillet and pour in the prepared glaze. Allow to bubble for 1-3 minutes until glossy.

If the sauce thickens too much, add a splash of water.

Lower the heat, add butter and dash of soy sauce, toss until butter melts.

Stir in toasted sesame oil off heat just before serving.

Add cooked vegetables back to skillet, serve over steamed rice, drizzle with mustard sauce, and garnish.