1/2 cup chili sauce 1/3 cup ketchup 1/3 cup prepared horseradish 1 1/2 teaspoon Worcestershire sauce 1/4 teaspoon sea salt, or to taste 3 tablespoons freshly squeezed lemon juice coarsely cracked freshly ground black pepper 1 pinch cayenne pepper 1/4 teaspoon celery seed 1/4 cup canned tomato puree (optional) 1/4 cup celery, strings removed and finely diced
Wash celery. Using a vegetable peeler, peel long, tough strings from outer side of celery (or break celery pieces and peel off strings).
Very finely chop the celery in a blender, as follows. Fill a blender container with cold water; add 1 1/2 inch pieces of celery to the water in the blender and pulse for a few seconds at a time until celery is finely chopped. Drain water and place celery on a clean paper towel to dry thoroughly.
Rinse blender container. Combine all ingredients (other than celery) in blender container and process until smooth. Add chopped celery and process for just a second, only long enough to mix (or stir in chopped celery by hand so that more texture is retained).
Season to taste with salt, pepper, and lemon zest, if desired. Store in a glass jar in refrigerator until ready to use.