Blend or process the egg yolks and herbs until smooth. Combine the vinegar, oil, rind and juice in a jug. With the food processor motor running, gradually pour the vinegar/oil mixture into the blended egg yolks etc. in a thin stream, blend until smooth and slightly thickened. Season to taste with black pepper and store in a screw-top jar in the fridge until ready to use. Shake well before adding to salad.