Chicken Salad

For the Chicken Salad:
1/2 cup walnuts, roughly chopped
Kosher salt
About 1 cup mayonnaise
1 heaping tablespoon Dijon mustard
1/2 lemon, juiced
2 celery stalks, small diced
2 tablespoons freshly chopped parsley leaves plus sprigs, for garnish
2 tablespoons extra-virgin olive oil
Freshly ground black pepper
2 cups shredded chicken meat, roughly chopped
8 slices sourdough bread, cut 1/2-inch thick
4 tablespoons unsalted butter, room temperature
1/4 cup cranberry sauce
1 green apple, thinly sliced
4 hard-boiled eggs, chopped
5 slices bacon, cooked until crisp, chopped