Our kitchen garden cook reveals her favourite recipes with watercress.

The health value of watercress has long been recognised. Hippocrates is believed to have built his first hospital beside a river where watercress grew, in about 400bc, to ensure his patients would have a constant supply of its healthy leaves. And, in the 16th century, the British herbalist John Gerard recommended them as a remedy for scurvy. Watercress sandwiches were so popular among London workmen by the early 1800s that beds were created along the River Itchen and several other chalkstreams.

Lemon and herb crusted salmon with watercress-and-spinach gnocchi (serves 4)

Ingredients
Crust
500g–600g boneless salmon fillet
3 small white crusty rolls
A handful of fresh parsley, finely chopped
50g butter
Zest of 1 lemon
Seasoning

Gnocci
750g potatoes
250g plain flour, plus 50g for working
A good pinch of salt
1 egg
1 handful watercress
1 handful baby spinach

Sauce
500g crème fraîche
Juice of 1 lemon
100g Parmesan, grated (plus extra for serving)
Seasoning
3 large handfuls of watercress
2 lemons

Method
Preheat your oven to 180˚C/350˚F/gas mark 4.

Pulse the white rolls in a food processor until they resemble coarse breadcrumbs. Add the parsley, butter, lemon zest and seasoning and pulse again until all the ingredients are just combined. Spoon the breadcrumbs over the salmon fillet on a lightly oiled oven tray, pressing them down gently to stay in place, then put the salmon in the oven for about 35–40 minutes while you prepare the gnocchi.

Peel the potatoes, cut them into small, even-sized pieces and boil in salted water until tender, but be careful not to overcook them or the gnocchi will be mushy. Put the potatoes through a ricer and tip into a large bowl or onto a suitable work surface before adding the flour, egg and salt.

Pulse the watercress and spinach in a food processor and scatter them over the potatoes, then mix everything together using a fork. Knead the mixture until it becomes a smooth dough. Divide it into chunks and roll it into long sausages, cutting them neatly into 1in pieces and placing them on a floured baking tray.

Drop batches of the gnocchi into a large saucepan of boiling water and remove with a slotted spoon once they float to the top, drizzling a little olive oil over them so they don’t stick to one another. Put the crème fraîche, lemon juice and Parmesan into a saucepan and heat through.

When the salmon is cooked, remove from the oven and arrange the gnocchi around it with the sauce drizzled all over, sprinkle grated Parmesan and the fresh watercress over the top and serve with lemon wedges.

More ways with watercress

Watercress, pear and pecorino salad 
Cut 2 firm pears into matchsticks before following suit with 100g of pecorino. Toss with a few handfuls of fresh watercress.

In an old jam jar, put 4tbspn olive oil, the juice of 1 lemon, 1tbspn natural yoghurt, 1tspn wholegrain mustard, 1tspn honey, 2tbspn finely chopped herbs and, having ensured the lid is tight, shake vigorously, then pour over the salad and mix well.

Brush four toasted slices of sourdough with olive oil and rub with garlic, then place one on each plate and top with the salad.

Watercress salsa verde
Put a handful of fresh watercress, 3 tinned anchovy fillets (fresh ones won’t be as flavoursome for this), 1 clove garlic, 1tbspn capers, the juice and zest from 1 lemon, 4tbspn olive oil, seasoning and 1 red chilli into a food processor and gently pulse into a coarse paste. Serve spooned over barbecued fish.