Put the chopped onion, beef mince and egg yolk in a mixing bowl and combine to make the burger mix, season. Take a handful of mix and form into a flat patty using your hands. Place a spoon of Castle MacLellan Mushroom Pâté in the centre and close. Make sure you fill any gaps and the meat is of equal thickness on each side of the pâté layer if possible.

Preheat the grill to hot. Cook the burgers under the grill for 15 minutes or until they are completely cooked through. Turn once to ensure they cook all the way through.

In a frying pan cook a slice of black pudding and place on the top of the burger.

Cut the ciabatta rolls in half and toast under the grill on both sides.

Layer the ciabatta with lettuce leaves, the burger and black pudding. Finish off with slices of tomato and red onion and sandwich in the ciabatta roll.