Combine all spices in a small bowl.
In a medium saucepan, whisk together tomato paste, sweetener, water, vinegar, and spices until combined well.
Bring to a boil, then reduce heat and cover, simmering over medium-low temperature for 25-30 minutes until thickened. Continue to cook if too thin.
Once ketchup reaches your desired thickness, remove from heat and cool. Store in an air-tight container in the refrigerator for up to 14 days.
Canning instructions: