Yellow Barn Tomato concentrate is available in store at Whole Foods and online. If you can't source it that way, look for tomato paste with less than 4 g carbs and no added sugar, high fructose corn syrup, or agave.
15turns of freshly ground black pepper from a mill1/4 tsp.
Combine all ingredients in a medium sized bowl and whisk together well.
Keep in a glass covered jar in the refrigerator. Keeps up to two weeks.
Note that it is the sherry vinegar that imparts the right flavor tang to this recipe. Do not substitute other types vinegar or it won't taste as good. If you prefer your ketchup a little thinner just add a little bit of water.**Store in the refrigerator in a glass jelly jar for up to 2 weeks. This ketchup will thicken up when cold. Before using, you may want to warm it for about 10-15 seconds in the microwave to warm it and make it easier to spread.