Put the cabbage, carrot and shredded spring onion in a bowl. Sprinkle over a good pinch of salt and mix well. Leave for 2 minutes and mix together with the mayonnaise.
For The Burgers
Peel and then finely dice the onions and mix them together with the minced beef, mustard, ketchup, thyme, salt and pepper. Work them together by hand until the ingredients are evenly mixed together.
Add the egg and breadcrumbs to the mixture and work it all together until it is fully combined.
Divide the mixture into four and roll them into balls. Flatten the balls into patties which are about each about 3cm thick. It is important to ensure that the thickness of all four burgers is the same to ensure that they cook evenly. Cover the patties and chill for at least 30 minutes.
While you are waiting for the patties, prepare the onion rings following the recommended cooking instructions on the back of the product pack
Sear the burger patties in a hot pan, getting a good even colour to both sides.
Pop the burgers into the oven for 6-8 minutes, or until cooked to your liking.
Add the bacon to the pan and fry until cooked
Allow the burgers to rest for 2-3 minutes once retrieved from the oven before adding the onion rings, followed by the cooked bacon and approximately 2 teaspoons of cranberry sauce. Carefully add the combination to the grill on a medium heat until the brie has melted and slightly browned
Cut the Brioche buns into two and add the lettuce. Place the combined burger patties to the bottom bun and garnish.