Put the eggs in a large saucepan of cold water. Bring to the boil and simmer gently for 10
minutes. Drain, then cool the eggs under cold running water. Remove the shells.
Place the egg yolk, lemon juice and dijon mustard in a food processor or blender and season.
With the motor running, slowly add the combined olive oil and safflower oil, drop by drop at first,
then slowly increasing the amount to a thin, steady stream as the mixture thickens. When all of the
oil has been added, put the mayonnaise in a large bowl and gently stir in the dill, creme fraiche
Roughly chop the eggs and fold into the mayonnaise. Transfer the salad to a serving bowl and use
scissors to cut the green tips from the mustard cress. Scatter over.