In a medium bowl or a small saucepan, combine 1 cup low-sodium soy sauce, 2 tablespoons toasted sesame oil, 2 tablespoons rice vinegar, 1 tablespoon mirin (or the sugar + water substitute), and 3 tablespoons water. Whisk until homogeneous.

Sesame & Aromatics

Add 3 tablespoons finely ground toasted sesame seeds, 2 teaspoons grated garlic, 1 teaspoon grated fresh ginger, and 2 tablespoons thinly sliced scallion greens to the liquid mixture. Whisk thoroughly to incorporate. Let sit 5–10 minutes to allow sesame seeds to hydrate and aromatics to mellow.

Sweetness, Umami & Heat

Stir in 2 tablespoons brown sugar, 1 tablespoon hoisin sauce, 3 tablespoons sesame paste, and 1 teaspoon chili oil (adjust to taste). Use a whisk or small blender to fully emulsify the sesame paste into the liquid for a smooth, creamy texture. Taste and adjust sweetness or heat as desired.

Thickening & Finish (Optional / Dairy-Free)

If you prefer a slightly thicker, clingy sauce like the restaurant version, make a slurry by mixing 1 teaspoon cornstarch with 1 tablespoon cold water until dissolved. Bring the sauce to a gentle simmer in a small saucepan over medium-low heat, whisking, then stir in the slurry. Simmer 1 minute until the sauce slightly thickens. Remove from heat.

Finish by whisking in 1 teaspoon toasted sesame oil and, if using, 1 teaspoon fresh lemon juice or additional rice vinegar to brighten the flavor. Season with 1/4 teaspoon salt, then let cool to room temperature. If you used a blender earlier, you can pulse once more for a satin texture.

Strain the sauce through a fine-mesh sieve into a clean container if you want a smooth, bottle-ready texture; reserve the solids for salads or dipping. Transfer sauce into an airtight jar or an 8 oz container. Chill at least 1 hour to let flavors meld; sauce will thicken slightly when chilled.