Herb Butter

Spinach
Watercress , stalks removed
Parsley leaves (only leaf)
Chervil leaves
Chive (chopped)
Tarragon leaves
Shallot chopped
Gherkins chopped
Anchovy fillets, drained chopped
Capers, drained chopped
Garlic cloved chopped
Salt
Black pepper
Cayenne pepper
Hard boiled, egg yolks
Raw egg yolks
Butter - Room temperature
Olive oil
White whine vinegar