Toss all ingredients in a bowl, starting with water (1/2 cup). Combine, and add more water until the ketchup has thickened to your liking.
Store in the fridge, and enjoy!
Notes
Lakanto, Swerve, or Erythritol. I stick toLakanto andSwerve which are a 1:1 swap with traditional sugar. If using a different brand of Erythritol, keep in mind it's 70% as sweet as sugar, so you may need to add more to taste.
Nutritional Information is based on a serving size of 2 Tablespoons. This recipe makes about 40 tablespoons of ketchup, so 2 tablespoons would give you 20 servings: