Mix the base sauce: In a bowl, whisk together soy sauce, brown sugar, sriracha, rice vinegar, garlic powder, and red chili flakes until smooth and the sugar begins to dissolve.
Prepare the cornstarch slurry: In a separate small bowl, whisk 1.5 tablespoons cornstarch with 2 tablespoons water until completely smooth. This helps the sauce thicken evenly without clumping.
Heat and thicken the sauce: Pour the mixed sauce into a small saucepan set over medium heat. Once it begins to steam, whisk in the cornstarch slurry and turn the heat to low. Continue cooking, stirring frequently, until the sauce becomes glossy and thick enough to coat the back of a spoon, about 2-5 minutes total. Adjust thickness by simmering longer or adding a splash of water as needed.
Cool and store the sauce: Remove from heat and let the sauce cool completely. Transfer to an airtight jar and refrigerate for up to 7 days. The sauce will thicken slightly in the fridge — whisk in a teaspoon of water when reheating if needed.
How to use the sauce for stir-frying: Heat a skillet with a neutral oil, add your veggies or tofu, and cook until crisp. Pour in your homemade teriyaki sauce and toss until everything is evenly coated and the sauce clings to the stir-fry.
Notes
Storage: Store in an airtight container in the fridge for up to one week. Reheat gently and add a splash of water if it thickens too much.Substitutions: Use tamari instead of soy sauce, maple syrup instead of brown sugar, or sambal in place of sriracha.Make it thicker: Add cornstarch slurry and simmer longer for a sticky glaze-style teriyaki sauce.Make it thinner: Skip the cornstarch and use extra vinegar if you want a lighter marinade.Variations: – Add fresh ginger for extra warmth and brightness. – Make a pineapple teriyaki by adding a splash of pineapple juice. – Add toasted sesame seeds directly into the sauce for nuttier flavor.