Mix together the granulated sweetener and xanthan gum.
Heat oil in a small saucepan over medium high heat. Add minced garlic, ginger, green onion, and red pepper flakes to oil. Saute until fragrant, about 1 minute.
Add lime juice, vinegar, ketchup, sriracha, and soy sauce to pan. Stir to combine and bring to a simmer, about 2-3 minutes.
Add sweetener/xanthan gum mixture to the sauce. Continue to simmer, stirring often, until sweetener is fully dissolved.
Stir in water, adding more or less to achieve desired consistency. Remove from heat.