Luckily I had a couple cans of tomato paste, and luckily I have made homemade ketchup a couple of times before. I have a recipe I've been tweaking, and this batch didn't come out half bad.
This is much less sweet than most store brands; the dominant flavor is tomato with a touch of sour from the vinegar, followed swiftly by salt and spice. It was great on the pork chops; I suspect it will be best with meats, but I may fry up a batch of skillet potatoes just to be sure.
6 oz. can of tomato paste
2 tsp sugar (feel free to substitute honey or sweetener)
1 tsp Italian dressing mix (I used Penzey's)
about 1/2 tsp seasoning salt or to taste
1/2 tsp black pepper
1/4 tsp white pepper
1/8 tsp allspice
pinch or 2 of cayenne pepper
1/2 cup cider vinegar
1/4 cup water
Combine tomato paste and spices. In a separate measuring cup, combine vinegar and water, and add to tomato paste mix in increments until desired consistency is reached. For best flavor, let sit for an hour or overnight in fridge. Apple juice can be used in place of water butI think that makes it too sweet.