Clean the radishes, wash the leaves and shake dry. Grate cheese. Finely mash the leaves, cheese, hazelnuts, oil and vinegar with a hand blender. Season pesto with salt and pepper. Wash the asparagus and cut off the woody ends.
Cover the asparagus and cook in boiling salted water for about 5 minutes.
Wash the radishes, halve them and cut them into slices, mix with pesto. Wash lettuce, dab dry and pluck roughly. Crumble feta coarsely. Arrange asparagus, radishes and salad on plates, sprinkle with feta.