Step 1

Melt butter in a large frying pan over low heat. Cook leeks until soft, about 15min. Add lemon zest and juice, cream cheese, most of the parmesan and prawns. Stir until cream cheese has melted and prawns are hot. Remove from heat.

Step 2

Meanwhile, bring a large pan of salted water to the boil and cook the farfalle according to pack instructions, about 10min.