Fill a pot with cold water and add vinegar. Carefully lower eggs into pot and boil for 15 minutes. Remove and place in cold water.
Once they are cold enough to handle, roll the eggs on the table or on a work plan to crack the shell slightly and allow some white to show (don't remove all the shell yet).
Pour some beetroot juice from a jar into a plastic food/ freezer bag. Place the eggs with their cracked shell in the freezer bag and leave to soak for 10 minutes (don't be tempted to leave for longer).
Then peel the eggs - you will see what looks like blood vessels.
Slice in half and arrange on a plate, using salad cream or mayo as glue. Use olives for eyes and add a big smile with ketchup.