Step 1

Toast the walnuts in a frying pan on a medium heat until golden, then put aside. Tear the stems out of the cavolo nero and discard, then blanch in boiling salted water for 4 minutes. Use tongs to carefully transfer two-thirds of the cavolo straight into a blender, leaving the pan of water on the heat. Remove the remaining cavolo to a board and roughly chop it. Add the mascarpone and most of the Gorgonzola to the blender and blitz until super-smooth, loosening with a splash of cooking water,

Step 2

if needed. Taste and season to perfection with sea salt and black pepper.

Step 4

Cook the gnocchi in the pan of boiling water for 3 minutes, or until they float to the surface, then drain and toss in the pan with the green sauce and chopped cavolo. Crumble over and fold through most of the walnuts, break over the remaining Gorgonzola and walnuts, then either serve straight away or pop under the grill for a few minutes, until beautifully gratinated.