Step 1 – Prepare the Marinade: Properly mix the following ingredients in the bowl: soy sauce, brown sugar, honey, garlic, and ginger. Add the chicken strips and let them sit for about 10–15 minutes to absorb the flavor.
Step 2 – Cook the Chicken: Cook the marinated chicken strips in a skillet with a little oil until brownish & perfectly cooked.
Step 3 – Make the Sweet Onion Sauce: In a saucepan combine sugar, vinegar, soy sauce, onion powder, mustard, and water. Simmer the mixture and add cornstarch slurry. Stir until the sauce thickens.
Step 4 – Coat the Chicken: Add a few tablespoons of sweet onion sauce to the cooked chicken. Toss & combine everything until the perfectly coated chicken.
Step 5 – Assemble the Sandwich: Slice the bread and add the teriyaki chicken. Top with lettuce, tomatoes, cucumbers, onions, and cheese if desired.
Step 6 – Serve: Drizzle extra sweet onion sauce on top, close the sandwich, and serve warm.