Step 1 Combine the cucumbers, onion and pepper in a nonmetallic bowl. Sprinkle with the salt and mix well. Let the vegetables stand 1 hour. Drain and return them to the same bowl.
Step 2 Combine the sugar, vinegar and celery and mustard seeds in another nonmetallic bowl. Stir until the sugar is dissolved. Pour the vinegar mixture over the vegetables. Cover and chill 24 hours to blend the flavors.