"A quick ketchup that is Whole30® compliant. Recipe uses sweet and tart apples to substitute for sugar in store-bought products. Whole30® recipes often use dates to sweeten, but here, the apples add more tartness and acid on the tongue."
Add tomato paste, apple, vinegar, garlic powder, salt, onion powder, and celery salt to a food processor. Blend until apple is fully incorporated and mixture has the consistency of ketchup. Scrape down sides continually to remove all lumps.
Pour blended mixture into a small saucepan. Bring to a simmer over low heat, stirring constantly, 8 to 10 minutes. Do not let boil. Season with ground pepper. Cool and transfer to the refrigerator.