In a medium-sized mixing bowl, combine the peanut butter, soy sauce, lime juice, honey, rice vinegar, sesame oil, and minced garlic. Add optional ginger or fish sauce if using.
Whisk vigorously until smooth and fully incorporated into a thick paste.
Gradually add warm water one tablespoon at a time, whisking continuously between additions until reaching your desired consistency.
Taste and adjust seasonings as needed - add more lime juice for acidity, more honey for sweetness, or more soy sauce for saltiness.
If desired, stir in red chili flakes for heat, adjusting to your preference.
If using, gently fold in chopped cilantro.
Transfer to a glass jar or airtight container, seal, and refrigerate for at least 15 minutes before serving to allow flavors to meld.
Before serving, shake or stir well as natural separation may occur.
