Cut the onions into rings, tomatoes, mushrooms and radishes into slices, dice the cucumber. Mix the lettuce with onion rings, tomato and mushroom slices, corn kernels, cucumber cubes, corn cobs and radishes. Place the ham and Edam cheese on top of each other and roll up together. Slice. Add these ham and cheese snails to the salad. Mix the sauce ingredients and pour over the salad.