Place the natural peanut butter in a small bowl and warm it slightly in the microwave or on low heat until it's soft and runny, about 10-15 seconds. This helps it whisk smoothly.
In the saucepan, whisk together the soy sauce, honey, and rice vinegar until well combined. Let it sit nearby for easy pouring.
Add the warm peanut butter to the soy mixture, whisking constantly until the sauce turns smooth and glossy. It should be silky with a nutty aroma.
If the sauce feels too thick, gradually add 1 tablespoon of warm water, whisking until it reaches a pourable, sauce-like consistency. Adjust with more water if needed.
Place the saucepan over low heat and gently warm the sauce, stirring constantly, until it is fragrant and slightly bubbling, about 2-3 minutes. Be careful not to overheat or burn the peanut butter.
Remove the sauce from heat and give it a final stir. Check the flavor—add more soy for saltiness, honey for sweetness, or vinegar for brightness if needed.
Let the sauce sit off the heat for a couple of minutes; this allows the flavors to meld and develop richer depth.
Pour the finished sauce into a small bowl or jar. It should be thick, shiny, and smooth—perfect for drizzling or dipping.
Serve the sauce warm or at room temperature, drizzled over roasted vegetables, grilled chicken, or stirred into a stir-fry for an extra layer of flavor.