Place chicken thighs in a 9 x 13 lightly oiled baking dish; season chicken lightly with salt and pepper; cover with foil and bake 30 minutes, or until internal temperature reaches 165ºF
Meanwhile, in a large stock pot, add oil and ½ stick of butter; add onion, celery and carrots; cook 5 minutes until tender
Once vegetables are tender, add remaining ½ stick of butter
Sprinkle flour over butter/vegetable mixture one tablespoon at a time, stirring constantly; cook for 5 minutes
Add milk and continue to stir
Add chicken broth, frozen peas and bay leaves
Allow to cook on medium low heat, covered while you shred the chicken
Add shredded chicken to the soup; allow to cook on medium low for 20 minutes; taste for salt and pepper; remove bay leaves and serve with puff pastry
Make the Puff Pastry
Roll out pastry sheets onto lightly oiled baking pan
Cut into quarters
Use a pastry brush to apply egg wash to pastry dough
Place in oven and bake 12-15 minutes, or until pastry is golden brown
Remove from oven and serve with soup
Notes
If you don't have any chicken broth but have chicken bouillon, make a cup of condensed cream of chicken soup and use it in the recipe.