Country Style Chicken Pot Pie

• 3 skinless, boneless chicken breasts
• 1 carrot, thinly sliced
• 1 red or green pepper, chopped
• 1 celery stalk, thinly sliced
• 1/2 onion, chopped
• 2 cups (500 mL) small broccoli florets
• 1/2 cup (125 mL) frozen peas vegetable oil
• 3 tbsp (45 mL) butter
• 1/4 cup (50 mL) all-purpose flour
• 1 1/2 cups (375 mL) milk
• 1 tbsp (15 mL) dried thyme leaves or rosemary or 3 tbsp (45 mL) finely chopped fresh thyme or rosemary
• 1 tsp (5 mL) salt
• 1/2 397-g pkg frozen puff pastry, thawed
• 1 egg, beaten

Preheat oven to 400F (200C). Cut chicken into 1-inch (2.5-cm) pieces. Prepare vegetables and measure out peas. Lightly coat a large frying pan with oil and set over medium-high heat. Add chicken. Stir often until lightly golden, 3 to 4 minutes. Add carrot, pepper, celery and onion. Stir often until onion begins to soften, 2 to 3 minutes. Remove chicken and vegetables to a bowl.