- Step 1: Prepare the Base 
- Preheat your oven to 425°F (220°C). 
- Heat olive oil in your Dutch oven over medium-high heat. 
- Season chicken pieces with salt and pepper, then add to the hot oil. 
- Cook chicken for 5-7 minutes until lightly browned on all sides. Remove and set aside. 
- Step 2: Build the Vegetable Foundation 
- Add diced onion to the same pot and cook for 3-4 minutes until softened. 
- Add carrots and celery and cook for another 5 minutes, stirring occasionally. 
- Add mushrooms and cook until they release their moisture, about 4-5 minutes. 
- Stir in minced garlic and cook for 1 minute until fragrant. 
- Step 3: Create the Creamy Sauce 
- Add butter to the pot and let it melt completely. 
- Sprinkle flour over the vegetables and stir constantly for 2 minutes to cook out the raw flour taste. 
- Gradually add chicken broth while stirring constantly to prevent lumps. 
- Bring to a simmer and cook until the sauce thickens, about 3-4 minutes. 
- Stir in heavy cream, thyme, and sage. Season with salt and pepper to taste. 
- Step 4: Combine and Top 
- Return chicken to the pot along with frozen peas and corn. 
- Stir gently to combine all ingredients evenly. 
- Roll out puff pastry slightly larger than your pot opening. 
- Place pastry over the pot, trimming excess and crimping edges to seal. 
- Brush with beaten egg for a golden finish. 
- Cut 4-5 small vents in the pastry to allow steam to escape. 
- Step 5: Bake to Perfection 
- Bake for 25-30 minutes until the pastry is golden brown and the filling is bubbling. 
- Let rest for 5-10 minutes before serving. 
- Garnish with fresh parsley and serve hot.