1 large skin-on, bone-in chicken breast about 12 to 14 ounces
2 1/2 tablespoons olive oil
Freshly ground black pepper
1 tablespoon white wine vinegar
1/2 small cucumber such as a Persian variety, halved, thinly sliced
1 small celery rib sliced thin
3 radishes quartered lengthwise, sliced thin
1 tablespoon herbs chopped; dill, chives or parsley, or a mix, for garnish
3 tablespoons creme fraiche
1 1/2 teaspoons prepared horseradish liquid drained off a little, plus more to taste
2 to 3 bread thin slices; rye, pumpernickel or another dense health bread, toasted