Prepare the fish. Pat dry with a kitchen towel and sprinkle with salt.
Take the monkfish out of the freezer the day before and leave in the fridge to defrost.
Heat a pan of water for the pasta.
Heat a frying pan on a medium-high flame. Add the butter, the oil, and then the fish. Turn the fish occasionally to sear on all sides.
Adding oil to butter in the pan prevents it from burning.
Place the pan with the monkfish into the oven at 70°C to rest for 10 minutes.
Now cook the pasta on a rolling boil until al dente ("to the bite"). Keep a fork to hand to test regularly.
Melt the butter in a saucepan with the olive oil, grate in the lemon rind, and drizzle in a little lemon juice.
Roughly chop the parsley and mix in to the emulsified butter.
Toss the cooked pasta in the parsley butter and sprinkle a little leftover parsley over the top.
Form a nest-like mound of pasta in the centre of the plate with the aid of a pasta spoon and lightly press down the monkfish on top.