Finely chop the jalapeno chilli or 1 tbsp M&S green sliced jalapenos. Finely grate the garlic cloves.
- 1 Preheat the oven to 200°C/ 180C fan/ Gas mark 6. Bake the ciabatta for 8-10 minutes.
- 2 Heat a pan until very hot, and season the steak and drizzle in a little oil before cooking for 2-3 minutes on each side. Rest for 5 minutes before slicing.
- 3 Mix the parsley, coriander, jalapeno chilli, red wine vinegar, oregano, garlic and olive oil together in a bowl and season.
- 4 Cut open the ciabatta and dress each side with the chimichurri. Scatter over the watercress and top with sliced steak.