Chicken & Cheddar Pot Pie

A delicious, cheesy pot pie filled with flavorful chicken and vegetables in a rich savory sauce. Marvelous! 1 tablespoon canola oil 1/2 cup chopped onion 1/2 cup chopped celery 3/4 cup thinly sliced carrots 1 cup frozen cut green beans, thawed 2 cups cooked chicken 1...