Combine the rhubarb, chipotle, sweetener, apple cider vinegar, and water in a medium saucepan. Bring to a boil and then simmer for 10 minutes.
Puree the mixture (a hand held immersion blender works best for this) and return to the stove.
Add the mustard powder, allspice, onion powder, salt, ground cloves, ketchup, oil, paprika, ginger, coriander, garlic powder, and fish sauce to the pan and stir well until combined.
Cook over low heat for another 5 minutes.