Peel cucumbers and slice 1/16 inch using a mandoline (or as thin as you can slice them with a knife). Put the cukes in a large bowl and 1/2 cup cold water. Add kosher salt and stir. Set aside for 1/2 hour.

Meanwhile put olive oil, vinegar and mayonnaise in a glass jar with a tight fitting lid. Shake vigorously for 20 seconds... this will make sure the mayonnaise is is well mixed.

Drain cukes and rinse well with cold water. Cukes will be limp. Add onions to the bowl, dressings and dill. Mix. Refrigerate if not used immediately. YUMMY!