Piece of fillet steak about 4cm thick and at room temperature
Ripe Tomato, sliced
Bread – I used a baguette but use whatever rocks your boat.
Good quality mayonnaise
Teaspoon of wholegrain mustard
Put a heavy metal skillet on a high heat.
season the piece of steak really well – most of the salt will come off when cooking and drizzle well with the olive oil.
When the skillet is smoking add the steak, keep turning the steak every 30s or so until it has colour on both sides and is done to your liking. About 5 mins for my medium rare-ish one. Then take the steak off the heat and place on a board to rest while you prep your bread.
Add one half of the bread to the pan to soak up and juices and lightly toast it. You can do the same to the other side if you want. To one side add a generous tablespoon of mayonnaise and smear it across the bread, then add a teaspoon of the mustard and mix it into the mayonnaise.
Slice the steak into strips. Use the un-mayonnaised side of bread to mop up any juices that have come out of the rested and sliced fillet.
First layer the tomato slices then top with the steak slices.
(As an option, I sometimes like to add grated cheese to it, and place under a hot grill for a minute to melt the cheese)