3 Just a Tin of Tomatoes
While you might not really think of it as ketchup, simply adding a tin of chopped tomatoes can do the precise same thing. Just by some tinned tomatoes from the store, then place them into a blender and blend them up. In fact, you could even serve them as they are!
Add sugar if you like, but there’s no reason not to serve the tomatoes just like this. This will still work great on top of a sausage roll or similar, but the difference is that it now adds a fresh juicy-ness instead of being something that makes the food seem more synthetic and less healthy. It’s great if the rest of the meal consists of greasy and oily meats and fries!