2 egg yolks
salt and pepper
1-1/2 cups oil (vegetable, corn or olive)
1 to 2 tablespoons lemon juice or white wine vinegar
1 to 2 teaspoons Dijon mustard
1 cup chopped parsley sprigs
1 cup chopped watercress sprigs
3 to 4 chopped scallions
1 chopped garlic clove
Put egg yolks in a bowl and add a pinch of salt. Beat well together. Add the oil, 1 to 2 teaspoons at a time, beating constantly with a whisk or electric mixer. After about 1/4 of the oil has been added very slowly and absorbed, beat in 1 to 2 teaspoons of the lemon juice or vinegar. Continue beating in the oil, in a thin, steady stream now. As the mayonnaise thickens, add another teaspoon of lemon juice or vinegar. When all the oil has been beaten in, add the mustard. Taste the mayonnaise and add more lemon juice or vinegar. Season with salt and pepper to taste.
If the mayonnaise is too thick, beat in a spoonful or two of water. Homemade mayonnaise will keep, covered, in the refrigerator, for up to 1 week.
Combine 1 cup each of the parsley sprigs and watercress sprigs in a blender or food processor. Add the chopped scallions and the garlic clove. Blend until coarse-fine. Add 1/2 cup mayonnaise and blend until smooth. Season to taste.