Wash and place the potato onto a bed of rock salt with the garlic cloves and place into a moderate oven180C for 45 minutes. Remove the garlic cloves after 10-15 minutes when they have roasted and are soft.
Remove the flesh from the potato skin and sieve or mash. Whilst the potato is still hot, blend the egg yolks with a pinch of salt, mustard and a splash of vinegar. Add a drizzle of oil and blend until smooth.
Add the warm potato and squeeze the garlic from the skin, add more oil and blend. Season with salt, a squeeze of lime and a generous amount of cracked black pepper.
Peal the prawns and remove the digestional tract.
Season the steak and prawns with olive oil, thinly sliced chilli and garlic, pepper & salt. Grill the steak and prawns.
Slice and grill the bread and smear generously with the black pepper and lime aioli. Place the steak on top and then a couple of prawns.
Toss the garlic with a touch of olive oil and a pinch of salt, place the leaves on top of the sandwiches.