Turkey Pie with Cobblestones

Ingredients:

Filling

• Olive oil to drizzle
• 2 large onions (1 cut into wedges, 1 diced)
• 1 half turkey breast with skin, boneless, weighing 1.1 kg.
• 3 sprigs of thyme + 2 tsp chopped thyme
• 4 tablespoons unsalted butter
• 2 carrots, chopped
• 2 stalks celery, chopped
• 1 tbsp. grainy mustard
• 1/4 cup premium flour
• 2 cups low-sodium chicken broth or turkey broth
• 0.5 cups whole milk
• 1 cup frozen green peas

Topping

• 1.5 cups premium flour
• 0.5 cup corn flour
• 2 tablespoons chopped fresh chives
• 2 tsp baking powder
• 2 teaspoons of sugar
• 1/4 teaspoon of baking soda
• 90 g chilled unsalted butter, diced
• 1 cup of sour milk or kefir, or a little less

Preparation:

1. Prepare the filling:
   Preheat the oven to 375°F (190°C) and spray a baking dish with olive oil. Arrange the onion slices in the dish and top with the turkey breast. Add the thyme sprigs, generously season the turkey with salt and black pepper, and drizzle with olive oil. Roast until a thermometer inserted into the thickest part of the breast registers 165°F (74°C), about 45 minutes. Let cool, then shred, discarding the skin. You should have about 4 cups of meat.
2. In a large cast-iron skillet, melt the butter over medium heat. Add the diced onion, chopped carrots, celery, and thyme, 1/2 teaspoon salt, and a pinch of freshly ground black pepper. Cook, stirring, until the vegetables are softened, about 7 minutes. Stir in the mustard, then sprinkle the flour over the vegetables. Cook, stirring, until the flour is toasted, about 2 minutes.
3. Stir in the broth, milk, and shredded turkey and bring to a boil. Reduce the heat to medium-low and simmer until the mixture thickens slightly, about 3 minutes. Remove from the heat and season with salt and pepper to taste.
4. Prepare the topping:
   In a medium bowl, whisk together the flour, cornmeal, green onion, baking powder, sugar, 3/4 teaspoon salt, baking soda, and a pinch of freshly ground black pepper. Using a pastry blender or your fingers, blend the butter into the flour mixture until it resembles coarse grains. Add 3/4 cup of buttermilk and mix until the dough comes together. If it looks too dry, gradually beat in up to 1/4 cup more buttermilk.
5. Stir the peas into the turkey filling. Spoon about 14 mounds of batter onto the top. Transfer the pan to the oven and bake until the topping is puffy and golden, about 25 minutes. Let rest for 5 minutes and serve.