Marinated and grilled swordfish

I mix plenty of extra virgin olive oil, chopped parsley, juice of half a lemon, salt and pepper in a bowl.I add the chopped garlic clove and make an emulsion.I wash the fish slices and dry with kitchen paper.I spread some marinade on a plate and put the swordfish on it.I cover with the remaining marinade.I cover with cling film and refrigerate for a couple of hours.Meanwhile, I peel and wash the potatoes, slice about 1 cm thick and blanch for 5 minutes in boiling water or in the microwave. I put them in a frying pan with a little clarified butter. I cook until golden, then add salt.I remove the fish half an hour before cooking. I heat a griddle until very hot, add the swordfish drained of marinade and cook for 3 minutes. I turn and cook the other side.Do not overcook swordfish or it becomes dry. I plate it with a little marinade and the potatoes, decorating with lemon and a parsley leaf.