( MAKES 4 )
Make steak more special by adding in this recipe which puts most of the focus on awesome onions, to create the best steak sandwich ever.
- Peel the onions, then slice into 2cm-thick rounds. Put the butter and oil into a large non-stick frying pan on a medium heat. Once the butter has melted, place the onions into the pan in a single layer and cook for 5 minutes. Pour in the vinegar, pop the lid on, reduce the heat to low and cook for around 35 minutes, or until beautifully golden and caramelised on the bottom only, adding splashes of water to loosen, if needed.
- Place the ciabatta into the oven, turn onto 110c and leave to warm through. Season the steak all over with sea salt and black pepper. Place a frying pan on a high heat. Once hot, drizzle the steak with olive oil, then put it into the pan and cook for 3 minutes on each side for medium, or to your liking. Remove to a plate, rest for 1 minute, then slice 1cm thick and toss through its own resting juices with a drizzle of extra virgin olive oil.
- Cut the ciabatta in half and rub the inside of each piece in the steak resting juices. Spread on some mustard, if you like, then layer over the caramelised onions, the steak and pinches of spinach. Pop the other piece of bread on top, press down lightly, carve up into decent chunks and get involved.