Mustard-Basil Vinaigrette

1. Combine mustard, egg yolks, lemon juice, garlic, mayonnaise, vinegars, herbs, and parsley in a blender or food processor.
2. Process briefly.
3. With machine running, add oil in a thin but steady stream.
4. Process until thikckened Seasoni to taste with salt and white pepper.
5. Use as a dressing for greens or a dip for vegetables.