Wash cucumber and cut into thin slices.

Slice onion and cut slices into 1/4s.

Place onion and cucumber into a bowl with salt and pepper. Toss with your fingers to distribute seasoning.

Heat vinegar and sugar in a sauce pan. Remove from heat when it starts to boil and add a handful of ice cubes.

Place cucumbers and onions into the jar and pour vinegar mix over all.

Cap and place in refrigerator for several hours or overnight. Keeps 1-2 weeks