4 boneless skinless chicken breast halves |
2 tablespoons olive oil |
1 teaspoon grated lemon, zest of |
1/4 cup fresh lemon juice |
1/2 cup chicken broth, mixed with |
2 teaspoons cornstarch |
2 tablespoons chilled unsalted butter |
1 small scallion, thinly sliced |
salt & freshly ground black pepper |