1. Soak the bread with enough water to cover. Let re-hydrate
at least 30 minutes.
2. Peel the onion, cut in half and also soak in some cold water
for 30 minutes.
3. Meanwhile, remove the seeds from the tomatoes and cut into
1/2-inch dice. Chop the celery and cucumber the same size as the
tomato. Remove the onion from the water and dice it the same size.
Combine all three in a large bowl.
4. Drain any excess water off the bread, squeezing with your
hands like ringing out a towel. Shred the bread into bite size
pieces. Combine the bread with the vegetables and chill for 1