Steak Sandwich with Caramelised Onions

Ingredients

• 400 g sirloin or rump steak
• 2 ciabatta rolls, halved
• 3 onions, finely sliced
• 30 g butter
• 4 tsp balsamic vinegar
• 1 tbsp Dijon mustard
• 40 g mayonnaise
• a large handful of rocket
• 1 tbsp olive oil

Method

1. Caramelise the onions

   Cook the onions in the butter over a low heat with a pinch of salt for a full thirty minutes, stirring now and then. There is no shortcut — high heat gives you burnt shreds, not sweetness.

   30 min

2. Deglaze

   Add the balsamic and cook until sticky and jammy.

3. Cook the steak

   Season the steak heavily and sear in a smoking-hot pan for two to three minutes a side for medium-rare.

   5 min

4. Rest and slice

   Rest the steak for five minutes, then slice thinly against the grain. Slicing early loses all the juice onto the board.

   5 min

5. Build

   Mix the mustard into the mayonnaise, spread on the rolls, then layer the onions, steak and rocket. Spoon any resting juices over the bread.