Preheat the oven to 375 degrees. Place the chicken breasts on a rimmed baking sheet and drizzle generously with olive oil. Sprinkle boths sides of each breast with salt, pepper, and garlic powder to taste. Roast for 40 minutes or until 165 degrees in the center. Once cooked, remove breasts from oven to rest and cube once the chicken has been able to rest for at least 10 minutes. Keep oven at 375.
In a large Dutch Oven, add the butter and onion on medium heat. Once the onions start to turn translucent (about 8 mins), add the garlic and cook for about 1-2 more minutes. Be sure not to let that garlic burn. Reduce to low heat and add the flour, stirring contstantly for about 1-2 minutes. You want to see that all of the flour has cooked into the butter.
Add the chicken stock and the apple cider vinegar. Simmer on low heat until the liquid has warmed through, then add the bouillon cubes. Stir until they dissolve. Add the heavy cream, stir to incorporate and bring to a boil. Then reduce to a low simmer. Add the peas, carrots and cubed chicken breasts. Let simmer for 5 minutes. Add salt and pepper to taste. For me, this was about 1 tbsp salt and 2 tsp cracked pepper. Turn off heat and stir in chopped parsley.
Roll out room temperature puff pastry with a rolling pin and a sprinkle of flour. Cut puff pastry to fit the top of individual, oven-safe bowls, with about 3/4 inch overhang. Fill each bowl about 3/4 of the way full with the pot pie filling and then drape the cut puff pastry dough on top. Sprinkle with salt and pepper. Place the bowls on a baking sheet and cook for 30 - 35 minutes or until the puff pastry is golden brown. Serve with a sprinkle of flaked sea salt and chopped parsley.