Creamy Chicken and Mushroom Stuffed Peppers

Ingredients (16)

• 5 green bell peppers
• 2 tablespoons olive oil
• 3 stalks celery
• 1 small onion
• 2 pounds cremini mushrooms
• 3 tablespoons butter
• 4 tablespoons flour
• 2 cups cold milk
• 2 cups chicken stock
• 1 teaspoon dried thyme
• 5 teaspoons dried mushrooms such as oyster or porcini
• 1/2 teaspoon kosher salt
• 1/2 teaspoon freshly ground black pepper
• 2 cups cooked chicken
• 2 cups cooked white rice
• 1 ¼ cups shredded cheese such as Monterey jack or cheddar