Combine. In a small saucepan, combine tamari, water, syrup, vinegar, ginger, garlic, 1/4 tsp. pepper and sesame oil. Whisk to combine.

Make Slurry. In a small bowl, whisk together cornstarch and 1 1/2 Tbsp. water. Pour this slurry into the pan with the teriyaki sauce ingredients.

Simmer To Thicken. Stir, cooking over medium heat until the mixture comes to a boil. Stir 1-2 minutes, or until stir-fry sauce has thickened. Stir in sesame seeds, if using.

Serve & Store! Remove sauce from heat and enjoy! Pour over stir-fried veggies, brush onto chicken or salmon, or stir into rice. Store in an airtight container in the fridge up to 1 week. Note that the sauce will thicken significantly in the refrigerator, so you'll want to reheat it on the stove or in the microwave to loosen it up before using any leftovers. 

Whisk together all ingredients in a small bowl (including cornstarch/water slurry).

Stir-fry your meat/veggies as you usually would. During the last 2-3 minutes of cooking, pour teriyaki sauce over stir-fried veggies/meat and cook over medium-high heat 2-3 minutes or until the stir fry sauce has slightly thickened.

Pour teriyaki sauce into a bag or airtight container with chicken, beef, or tofu. Chill in the refrigerator and marinate 2-3 hours at least to infuse with teriyaki flavor. Drain & discard excess marinade and cook as desired!