This is something that you can make very quickly , there is no time to be away from the cooker.
Heat up a dry pan and throw in the bacon , it will start to sweat and loose fat quite rapidly , so you really don't need any extra fat here. Keep stirring until your bacon bits are golden brown (nor charred) .
Add the parsley and fry it for about 30 seconds so it starts loosing moisture and has given some taste to the fat.
Add the tomato ketchup, some pepper and salt and let the whole thing reduce until your ketchup is darker than usual (keep turning in it with a wooden spatula making sure nothing sticks).
Add the cubed tomato, quickly stir it in the now heavily concentrated mixture in your pan, and let the whole heat up for a few seconds. The tomato doesn't have to 'cook', it just has to be warmed up. The whole thing should now have the consistency of thick tomato sauce.
Serve inside a toasted soft bun (cut in half and toasted in a toaster or lightly fried if you don't have a toaster wide enough).
Enjoy your snack and don't forget to give some feedback.