Heat a tablespoon of oil in a frying pan. Add in the onion and sauté for a couple of minutes until softened. Remove from the pan and allow to cool.
Place the mince, cooled onion, garlic, tomato purée, Worcestershire Sauce, parsley and seasoning in a bowl, mix well then shape into four burgers. Heat a little oil in a frying pan and cook the burgers for 4-5 minutes on each side until fully cooked. They can also be cooked on the barbecue.
Put a spoonful of relish on the bottom half of each bun. Follow with a handful of salad leaves and a burger then top with a slice of cheese and a slice of streaky bacon.
Beetroot relish: Heat a tablespoon of oil in a saucepan over a medium heat. Add in the onion and garlic and sauté gently for about 5 minutes until softened. Remove from the pan.
Heat a little more oil and then sauté the beetroot for 10 minutes, stirring occasionally. Add back in the onion and garlic mixture along with the remaining ingredients. Simmer gently for 35-40 minutes until it thickens to a jam-like consistency.
Allow to cool then store in a fridge. It will keep for 3-4 weeks.
Serve with a green salad.