Combine all of the burger ingredients together and form into 4 patties.
Fry over a medium heat in a little oil, for 5 – 10 minutes on each side until golden brown and thoroughly cooked. Set aside to rest and keep warm.
Place the cooked burgers onto a baking tray and top with 1 slice of beef tomato, a spoonful of onion marmalade and a slice of blue cheese, then pop the tray into a hot oven for 5 minutes until the cheese begins to melt.
Meanwhile arrange some rocket leaves on the top of each toasted bun, remove the burgers from the oven and place on each of the buns.
Serve with salad.