For Biscuits
2 cups self-rising flour
3⁄8 cup cold unsalted butter, cut into 1/2-inch pieces
1 cup whole milk
all-purpose flour, for dusting
For Chicken In Gravy
1 medium onion, finely chopped
1 1⁄2 carrots, finely chopped
1 1⁄2 celery ribs, finely chopped
1⁄4 teaspoon salt
3⁄4 teaspoon black pepper
3 tablespoons unsalted butter
2 tablespoons all-purpose flour
1 3⁄4 cups reduced-sodium chicken broth (14 fl oz)
1⁄2 teaspoon chopped fresh thyme
1⁄2 cup half-and-half
3 cups chopped cooked chicken (from a 3- to 3 1/2-lb rotisserie chicken)
1⁄2 teaspoon fresh lemon juice