Marinate the monkfish in the herb salt. Peel the asparagus and bring to the boil 3-6 minutes with a little salt. Turn off the heat and leave to cool in the liquid. Squeeze the lemons over the vine tomatoes and scatter a little salt and pepper over the top. Then place the monkfish in a casserole on non-stick baking paper and bake in a preheated oven for 6 minutes at 140 degrees. Add the tomatoes for the last minute. Remove some liquid and arrange on two plates. Place the monkfish on top, arrange the vine tomatoes around it and spoon some of the thickened asparagus liquid over the monkfish. Finally garnish with the watercress for a spicy twist.
Tip: for an elegant look alternate the tomatoes with pieces of monkfish on a skewer before serving.