Heat sesame oil in a small saucepan over medium-low heat. Add minced garlic and grated ginger, sautéing for 60-90 seconds until fragrant but not browned.
Reduce heat to low. Add peanut butter and coconut milk, whisking constantly until completely smooth and integrated (approximately 2-3 minutes). Maintain temperature below 180°F to prevent separation.
Add soy sauce and brown sugar, whisking to fully dissolve sugar crystals (approximately 1 minute).
Add warm water 1 tablespoon at a time until desired consistency is reached. For dipping sauce, aim for honey-like viscosity; for coating chicken, create a slightly thinner consistency.
Add rice vinegar, lime juice, and salt. Whisk to incorporate.
Add sambal oelek or sriracha to achieve desired spice level.
Allow sauce to simmer for 2-3 minutes on lowest heat setting, whisking occasionally to homogenize all flavors. The sauce should coat the back of a spoon with a smooth, even layer.