Cook the spaghetti according to pack
instructions, adding the peas for the final
2 mins. Meanwhile, heat the oil in a frying
pan, add the leeks, then gently cook for
about 5 mins until softened. Stir in the
pesto and 3 tbsp of the pasta cooking
water, then simmer for a few mins.
Drain the pasta and peas, then add
to the frying pan, tossing everything
together. Divide between 2 warm
bowls and sprinkle with a little grated
Parmesan, if using.