Chicken Pot Pie

Name: Chicken Pot Pie
Prep time: 20 min
Cook time: 1 h 10 min
Total time: 1 h 30 min
Cuisine: American
Ingredients: 1 boneless, skinless chicken breast (about ⅔ lb.) ($3.33); 1 Tbsp cooking oil ($0.04); 1 yellow onion ($0.38); 4 Tbsp butter ($0.50); 4 Tbsp flour ($0.04); 1 cup chicken broth ($0.13); 1/2 cup whole milk ($0.10); 1/4 tsp dried thyme ($0.03); 1/4 tsp rubbed sage ($0.03); 1/4 tsp black pepper ($0.02); 3/4 tsp salt ($0.05); 12 oz. frozen mixed vegetables ($1.25); 1 double pie crust ($2.34); 1 egg (optional) ($0.20)