Sweet Potato Chicken Pot Pie

This is a delicious and moderately healthy version of chicken pot pie.  I've never actually had a pot pie before today but Heath had the great idea of using sweet potatoes so I gave it a whirl and YUM!

INGREDIENTS
2 Chicken Breasts
1 1/2 cups orange juice
1/4 cup brown sugar
1 TB extra virgin olive oil
1 Large Sweet Potato, peeled and cubed (small)
1 Medium Onion, diced
3 stalks celery, diced
2 cloves garlic
1 1/2 cups chicken broth
1 1/2 cups milk
2 TB all purpose flour
1 cup frozen peas
1 cup frozen carrots
1 cup frozen green beans
1 package puff pastry (dethawed)
Salt, Pepper, *Old Bay (optional)

DO AHEAD: (this will save you some time, otherwise it takes a while!)

1. Chicken:
      1. Stir brown sugar into orange juice; put into large pan
      2. Put whole chicken breasts into orange juice solution, cook on low (I had it at a 3 on my
          electric stovetop) until cooked through (15 ish minutes)
      3.  Let chicken cool in orange juice.  Pull/pick apart chicken once cooled enough to handle

2. Sweet Potatoes:
     1. Peel and cube/dice potatoes (depending on how big you want them)
     2.  Boil until al dente, tender but not too mushy.
     3.  Set aside.

ASSEMBLY:
*Preheat oven to 420 F
1. Saute diced onion and celery until opaque in a dutch oven.
2. Add garlic, then milk;
3. In a separate bowl, stir flour into warm chicken broth; add to dutch oven; stir to combine
4. Bring mixture to a boil
5. Add peas, carrots, green beans, and bring mixture to a boil again; reduce heat and simmer for about
     10 minutes
6. Add pulled chicken and sweet potatoes to pot, stir to combine and heat until all ingredients are heated through.  Season with salt and pepper to taste (I put in about 1/4 tsp of Old Bay for a little extra kick)
7. Line a casserole dish (i used a medium sized round one....) with a puff pastry sheet.
8. Pour filling into puff pastry (I had a lot of leftovers to bring for lunches this week that didn't fit into the crust), top with puff pastry cut outs (or a flat layer with slits cut into it to vent)
9. Brush egg wash onto top to prevent burning.
10.  Bake uncovered for about 25 minutes (until puff pastry is puffed and golden brown), let sit for about 10 minutes then DIG IN