Ingredients:

  • 2 tablespoons (30 ml) olive oil
  • 1 large onion, chopped (about 1 cup / 150g)
  • 2 carrots, peeled and chopped (about 1 cup / 120g)
  • 2 celery stalks, chopped (about 1 cup / 100g)
  • ½ teaspoon dried thyme
  • ¼ teaspoon dried rosemary
  • 4 tablespoons (60g) unsalted butter
  • ⅓ cup (40g) all-purpose flour
  • 3 cups (720 ml) chicken broth
  • 1 cup (240 ml) whole milk
  • 1 teaspoon salt, or to taste
  • ½ teaspoon black pepper, or to taste
  • 2 cups (300g) cooked chicken, shredded or diced (about 2 large chicken breasts)
  • 1 cup (150g) frozen peas
  • 1 cup (150g) frozen corn
  • 1 ½ cups (190g) all-purpose flour
  • ¾ teaspoon baking powder
  • ½ teaspoon salt
  • ½ cup (113g) (1 stick) cold unsalted butter, cubed
  • ½ cup (120 ml) cold milk
  • 1 large egg
  • 1 tablespoon milk

Instructions:

  1. Heat olive oil in a large skillet. Add onion, carrots, and celery; cook until softened, about 5-7 minutes. Stir in thyme and rosemary.
  2. Melt butter in the skillet. Whisk in flour and cook for 1 minute, until a paste forms.
  3. Gradually whisk in chicken broth and milk. Bring to a simmer, stirring constantly, until thickened (about 5-7 minutes). Season with salt and pepper.
  4. Stir in cooked chicken, peas, and corn into the sauce.
  5. In a bowl, whisk together flour, baking powder, and salt. Cut in cold butter until the mixture resembles coarse crumbs. Stir in cold milk until a dough forms.
  6. Pour the chicken filling into the baking dish.
  7. Roll out the dough on a lightly floured surface, cut to fit baking dish, and place atop the filling. Alternatively, use drop biscuits.
  8. Whisk egg and milk together. Brush over the crust. Cut slits in the crust to vent steam. Bake in a preheated oven at 375°F (190°C) for 35-40 minutes, or until the crust is golden brown and the filling is bubbly.
  9. Let the casserole cool for 10-15 minutes before serving.