Chicken Pot Pie

Name: Chicken Pot Pie
Ingredients: 1 chicken breast ; chunks + 2tsp oil for stir frying; 2/3 cup diced carrots (about 2 carrots); 1 cup celery ; diced, (about 2 ribs); 1/3 cup diced ham (this is optional); 1 cup onion ; diced (about 1/2 large onion); 2 cloves garlic; 2 tsp oil; 3 cups potatoes ; diced (about 4 medium potatoes); 4 tbsp flour ; (up to 5); 1 cup milk; 1 cup peas; 1 bay leaf; 1 tsp thyme; 1 salt and pepper to taste; Puff pastry (homemade or store-bought) for crust; 1 egg ; beaten, for glaze