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