PreparationMake biscuits: Put oven rack in middle position and preheat oven to 450°F. Blend together flour and butter in a bowl with a pastry blender or your fingertips until mixture resembles coarse meal with some small (roughly pea-size) butter lumps. Stir in milk with a fork just until a sticky dough forms. Turn dough out onto a floured surface and gently knead 7 or 8 times. (Do not overwork, or biscuits will be tough.) Pat dough into a 9- by 6-inch rectangle on a lightly floured surface, then cut into 6 (3-inch) squares. Arrange squares 1 inch apart on an ungreased baking sheet and bake until golden brown, 15 to 18 minutes. Cool to warm on baking sheet on a rack. Make chicken in gravy while biscuits bake: Cook onion, carrot, celery, salt, and pepper in butter in a 10-inch heavy skillet over moderate heat, stirring occasionally, until vegetables are softened, 8 to 10 minutes. Sprinkle flour over vegetables and cook, stirring, 1 minute. Stir in broth and thyme and bring to a boil, stirring, then boil over moderate heat, stirring occasionally, 2 minutes. Add half-and-half and chicken to gravy and gently simmer until chicken is heated through, about 3 minutes. Stir in lemon juice. To serve: Halve biscuits horizontally and put each bottom half in a shallow bowl. Spoon chicken in gravy over biscuit bottoms and cover with biscuit tops.
PreparationMake biscuits: Put oven rack in middle position and preheat oven to 450°F. Blend together flour and butter in a bowl with a pastry blender or your fingertips until mixture resembles coarse meal with some small (roughly pea-size) butter lumps. Stir in milk with a fork just until a sticky dough forms. Turn dough out onto a floured surface and gently knead 7 or 8 times. (Do not overwork, or biscuits will be tough.) Pat dough into a 9- by 6-inch rectangle on a lightly floured surface, then cut into 6 (3-inch) squares. Arrange squares 1 inch apart on an ungreased baking sheet and bake until golden brown, 15 to 18 minutes. Cool to warm on baking sheet on a rack. Make chicken in gravy while biscuits bake: Cook onion, carrot, celery, salt, and pepper in butter in a 10-inch heavy skillet over moderate heat, stirring occasionally, until vegetables are softened, 8 to 10 minutes. Sprinkle flour over vegetables and cook, stirring, 1 minute. Stir in broth and thyme and bring to a boil, stirring, then boil over moderate heat, stirring occasionally, 2 minutes. Add half-and-half and chicken to gravy and gently simmer until chicken is heated through, about 3 minutes. Stir in lemon juice. To serve: Halve biscuits horizontally and put each bottom half in a shallow bowl. Spoon chicken in gravy over biscuit bottoms and cover with biscuit tops.