Sandwich Night: The Sliced Chicken and Mushroom Rachael

Name: Sandwich Night: The Sliced Chicken and Mushroom Rachael
Ingredients: 4 tablespoons (1/2 stick) butter; 1/2 pound baby portobello mushrooms, sliced; 2 tablespoons fresh sage leaves, thinly sliced, or 1 1/2 teaspoons dried sage; Salt and freshly ground black pepper; 1 large onion, thinly sliced; 1-pound package sauerkraut, rinsed and drained; 4 (6-ounce) boneless skinless chicken breast halves; Grill seasoning blend (recommended: McCormick Montreal Steak Seasoning); 1 tablespoon extra-virgin olive oil; 1/2 cup sour cream; 2 tablespoons dill relish; 3 tablespoons ketchup; 2 tablespoons chopped fresh dill or 1 1/2 teaspoons dried dill; 2 tablespoons chopped fresh flat-leaf parsley leaves; 8 slices marble rye, rye, or pumpernickel bread; 8 slices Gruyere or deli Swiss cheese; 4 large deli pickles; 1 bunch radishes, halved and salted