1. Preheat oven to 350 degrees Fahrenheit. Put chicken breasts on baking sheet, coat with olive oil and sprinkle with salt and pepper. Roast for 20-30 minutes until cooked through.
2. Set chicken aside to cool.
3. Chop chicken into small cubes and set aside.
4. In small saucepan over medium heat (or tea kettle, in my case), dissolve bouillon into stock.
5. In large pot over medium heat add butter and cook onions until softened, about 10 minutes.
6. Add flour and cook, stirring, over low heat, for 2 minutes.
7. Add hot stock to onion mixture while stirring.
8. Simmer until all flour bits have dissolved, about 2 minutes.
9. Add 2 teaspoons salt, 1/2 teaspoon pepper, heavy cream, carrots, potatoes, peas, and cooked chicken. Mix well. Remove from heat.
10. Roll out puff pastry on a floured surface until 1/4 inch thick. Using foil containers to gauge size, cut pastry into rectangles, leaving enough space to fold over edges of containers.
11. Increase oven temperature to 375 degrees Fahrenheit.
12. Fill foil containers with chicken and vegetable mixture, all the way to the top.
13. Brush sides and edges of foil containers with egg. Place pastry over foil containers and press edges so the egg mixture holds them against the sides. If freezing, stop here, cover pies with foil and place in freezer. Start at step 14 when you take them out of the freezer.
14. Brush tops of pot pies with egg and cut several slits to allow steam to escape.
15. Place pies on baking sheet and cook for 1 hour.