Spring Chicken and Biscuits

Name: Spring Chicken and Biscuits
Ingredients: 1 cup and two tablespoons baking mix (not with buttermilk); 1⁄3 cup milk; 4 medium boneless skinless chicken breast halves (1 1/2 pounds); salt and pepper; 5 teaspoons olive oil; 2 medium carrots, chopped; 1 small onion, chopped (4-6 ounces); 1 stalk celery, chopped; 1 cup reduced-sodium chicken broth; 2 tablespoons cornstarch; 1⁄2 cup milk; 1 cup frozen peas, thawed; 1 tablespoon chopped fresh dill, plus additional sprigs for garnish; 2 teaspoons fresh lemon juice