Remove the ends of the sugar snaps and, if necessary, the string running down the sugar snap. Cut off the tips of the haricots verts.
Blanch the sugar snaps and the haricots verts for a few minutes in boiling water and rinse them under cold water or put them in iced water.
Clean the lettuce. Arrange the leaves nicely on two plates.
Mix the sugar snaps and haricots verts with the pesto and divide between the plates.
Chop the walnuts coarsely and divide over the vegetables. Finish with flakes of Parmesan cheese (grated is also an option).