Peel your onions, then slice in half. Thinly slice your onions into half rings.

Melt butter in a frying pan, and add onions once the butter has melted.

Stir frequently and cook the onions for 3-5 minutes until translucent.

Add the honey, stirring to combine, and cook the onions for a further 5-10 minutes, until they are dark brown and very soft.

Spread the softened butter on one side of each slice of sourdough.

Preheat a large frying pan over low-medium heat.

Sandwich the buttered sides together, creating 2 sandwiches, then spread grainy mustard on each sandwich.

Grate your two cheeses, toss to combine then add half the cheese blend on each sandwich.

Add your caramelized onions on top of the cheese.

Pick up the top (loaded) half of the sandwich and place it on the pre-heated frying pan. The buttered side should be on the pan now. Then flip the remaining top half so the buttered side is facing up and place it on top of the sandwich.

Cook this side for 3-5 minutes, or until golden on the bottom.

Using a spatula, flip the sandwich so the other buttered side is now on the pan. Cook for another 3 minutes until the cheese has completely melted.

Take off the pan, slice and enjoy!