Method

1. For the aioli with potato: preheat the oven to 180C/gas 4.

2. Scatter the rock salt over a baking tray. Wash the potato, place on top of the rock salt and scatter over the garlic cloves. Place in the oven to bake. Remove the garlic cloves after 10-15 minutes, or when they are soft, and remove the potato from the oven after 45 minutes.

3. With a sharp knife, carefully remove the flesh from the potato skin. Mash the potato until smooth. While the potato is still hot, whisk the egg yolks with a pinch of salt, the mustard and a splash of vinegar in a bowl. Gradually add all but a splash of the oil, whisking with each addition.

4. Add the warm potato, squeeze the garlic from its skin and stir that in too. Stir in the final splash of olive oil and season with salt, lime juice and freshly ground black pepper, to taste.

5. For the reef and beef: season the steak and prawns with the olive oil, chilli, oregano, lemon juice and garlic in a non-reactive bowl. Season with pepper and salt.

6. Preheat the grill to hot.

7. Grill the steak and prawns on a tray under the hot grill until cooked to your liking, turning once.

8. To serve, toast or grill the bread on both sides, then smear generously with aioli. For each serving, place the steak on top of one of the pieces of toast and then top with a couple of prawns. Toss the rocket with a touch of olive oil and a pinch of salt in a small bowl and then place the leaves on top of the sandwiches. Serve at once.