1/2 cup very thinly sliced red onion
3 cups cubed light rye bread
1 garlic clove, peeled
Fine sea salt
1/4 cup extra-virgin olive oil
1 tablespoon red wine vinegar
1 pound tomatoes, cored and cut into 1-inch chunks
2 medium pickling or Persian cucumbers or 1 large European cucumber
2 stalks celery, thinly sliced
3/4 cup basil leaves, large leaves torn
1/4 pound sliced pastrami, coarsely chopped
1/4 cup flat-leaf parsley leaves