Creamy Chicken and Mushroom {Crock} Potpie

8 oz. cremini mushrooms, stems trimmed and halved

4 carrots, cut into 1-inch pieces

1 medium onion, chopped

1/3 c. flour

2 sprigs fresh thyme

1 bay leaf

1/2 c. water

1 1/2 pounds boneless, skinless chicken thighs (about 8)

Kosher salt and black pepper

1 sheet puff pastry (half a 17.3-ounce package), thawed

1 c. frozen peas

1 c. frozen green beans

1/3 c. heavy cream

• In a 4 to 6 quart slow cooker, mix together the mushrooms, carrots, onion, flour, thyme, bay leaf, and 1/2 c. water. Place the chicken on top; season with 1 t. salt and 1/4 t. pepper.
• Cover and cook until the chicken and vegetables are tender, on low for 7 to 8 hours or on high for 4 to 5 hours. 
• 30 minutes before serving, heat oven to 425. Using a large glass, cut the pastry into 4 circles. Place on a baking sheet and bake until golden, 8 to 10 minutes. 
• Ten minutes before serving, add the peas, green beans, cream, and 1/2 t. salt to the chicken mixture and stir to combine. Cover and cook on high until heated through, 5 to 10 minutes more. To serve, place the chicken mixture in bowls and top with the pastry rounds.