Pick only parsley leaves, otherwise the sauce will be very bitter. Add all the other salsa verde ingredients in a food processor and blitz until smooth. Taste and season with salt and pepper and the lemon juice.
Cut all the tomatoes in half. Cook the potatoes until soft and half again.
Blanch the green beans/asparagus for 1 minute 30 seconds. As they are still hot, trim into 2inch pieces and add to the salsa. The same with the potatoes. This helps the salsa flavour the ingredients, rather than sit on the ingredients.
Heat a frying pan over a medium high heat. Add the fish skin side down. Season with salt and pepper. Leave in the pan until all the sides are white (cooked) and the skin is just turning brown at the edges. Flip, cook for 1 minute then turn the heat off. Leave the fish in the pan as you plate up.
Once you’ve plated up, then place a fish fillet directly on top.