Spring has suddenly arrived and the the warmer weather is making the rocket in my vegetable patch race away. What I cannot use fresh I make into pesto. Although pesto made with basil is the best known, it is a very useful method of preserving all the more delicate herbs that do not dry well.

This recipe combines the peppery flavour of rocket with the sweetness of roasted walnuts and the acid of fresh lemon juice, but you can also make a more oriental version with fresh coriander, lemon grass and lime bound together with either sesame oil or olive oil. These sauces will keep up to ten days in the fridge, but if you pack the paste into sterilised jars making sure that there are no air bubbles and then pour at least one centimeter of oil on it to create a seal, it will keep for several months if stored in a cool dark place.

For Rocket and Walnut Pesto you will need;

100 gms rocket – washed and dried

100gms walnut pieces

1 stem spring garlic

walnut or extra virgen oilive oil

the juice of half a lemon

salt

Firstly roast the walnuts. Heat a thick bottomed pan on a low heat and add the walnuts.  Toss from time to time to turn the nuts. They are done when the oils in the walnuts give off a rich odour.

Put the nuts together with the rocket, chopped garlic and a couple of tablespoons of oil into the food processor and whizz to a pulp. Add more oil to get to a paste consistency. Add the salt and lemon juice bit by bit tasting as you go along until you find that the seasoning and balance is right.

Thats it. This pesto goes particularly well with fish and that is what I am having it with today. I’ve used it as a sauce on the pasta shells to accompany a piece of grilled tuna.