In a small saucepan, add 1/2 cup of low-sodium gluten-free tamari and 1/4 cup of water. Then incorporate 1/4 cup of maple syrup, 2 tablespoons of rice vinegar, 1 tablespoon of minced ginger, 1 clove of minced garlic, 1/4 teaspoon of black pepper, and 1/4 teaspoon of sesame oil. Whisk everything together over medium heat, allowing the mixture to start warming up, which will take about 2-3 minutes.

While the sauce simmers, prepare the thickening agent. In a separate small bowl, combine 1 ½ tablespoons of cornstarch with 1 ½ tablespoons of water. Whisk thoroughly until you have a smooth slurry, ensuring there are no lumps. This will help give your homemade gluten-free teriyaki sauce that desirable glossy, thick texture.

Slowly pour the cornstarch slurry into the saucepan while stirring continuously. Increase the heat slightly to bring the mixture to a gentle boil, keeping a close eye on it. Cook for about 1-2 minutes until the sauce visibly thickens and coats the back of a spoon.

Once thickened, remove the saucepan from heat and optionally stir in a sprinkle of sesame seeds for added crunch and flavor. Let the sauce cool slightly before using it over your favorite stir-fried vegetables or grilled proteins.