Combine all the ingredients in a small saucepan over medium heat and whisk until it's well incorporated.
When it boils, lower the heat to simmer for 5 minutes while stirring.
Ketchup will splatter so be careful since it will be hot.
Remove the saucepan from the heat, cover until cool.
Transfer the ketchup in a glass bottle and refrigerate for up to 2 weeks.
Notes
Consistency - if you prefer thinner ketchup, you can add more water until you reach the consistency you like. Sweetness - use more honey if you prefer sweeter ketchup. Storage - since there are no preservatives in homemade ketchup, it will be good for only 2 weeks in the refrigerator. I like to make small batches at a time for freshness.