Chicken Breasts Stuffed with Goat Cheese and Basil

Name: Chicken Breasts Stuffed with Goat Cheese and Basil
Ingredients: 4 boneless chicken breast halves, skinned; 1/2 cup fresh goat cheese (such as Montrachet) (about 4 ounces); 2 green onions, thinly sliced; 3 basil leaves, shredded or 1 teaspoon dried, crumbled; Salt and freshly ground pepper; 1 egg, beaten to blend; 1/2 cup dry breadcrumbs; 2 tablespoons (1/4 stick) unsalted butter melted; 1/4 cup (1/2 stick) unsalted butter; 1/2 pound mushrooms, sliced; 1/4 cup dry white wine; 2/3 cup chicken stock or canned low-salt broth; 4 tablespoons chilled unsalted butter (1/2 stick), cut into 4 pieces; Salt and pepper