1. Fry the bread in butter, until it is golden and crisp.
2. Slice the onions and heat in a pan with 1 tablespoon of butter. Cook for 8-10 minutes, until lightly golden.
3. Cut the apple into wedges and cook them with the onion for 1-2 minutes. Add a pinch of salt and some thyme.
4. Mix the mayonnaise and chipotle together, add salt to taste.
5. On a high heat, add some butter to a pan and cook the steaks. Season with salt and pepper.
6. Slice the steak just before you assemble your sandwich.
7. Spread your mayonnaise onto the bread and top with rucola and radicchio, onions, slices of Castello Velvet Blue and steak. Add more thyme if prefered. Serve straight away.
Toasting the bread well before adding the filling is important. This is what makes it crunchy so make sure to use enough butter and roast it all the way through on both sides.
After adding the Velvet Blue on top of the steak, you can put the open-faced sandwich in the oven until it starts to melt; just remember not to leave it for too long so the salad goes soggy.