An excellent mayonnaise or thick dressing based on potato. Try it with tomato salad or with a cold salmon trout or salmon or with any grilled fish.

3 oz. sieved, mashed potato (without butter or milk)
2 yolks of hard boiled eggs
1 tsp. dry mustard
1 tsp. salt
3 tbsp. olive oil
1 tbsp. wine vinegar
1/2 tsp. anchovy essence
1/2 tsp. onion juice from pounded onion OR 1/2 tsp. of onion salt

Beat all the dry ingredients into the potato. Stir in the oil and vinegar in alternate small quantities. Beat well again, add the onion juice and anchovy and give a final beating. Or put all ingredients together into blender. The sauce should be very smooth and of the consistency of very thick cream. It may be thinned with a very little extra vinegar and additional olive oil if necessary