Heat the oven to 400 degrees F.
Melt the butter in a large skillet over medium-high heat. Add the chopped onion and saute until translucent, 10 to 12 minutes. Whisk in the flour and cook for 2 minutes, or until the flour smells nutty and no longer looks dry. Whisk in the stock, sherry, and Salt Pepper + Three Chiles and bring to a simmer to thicken. Remove this sauce from the heat and gently stir in the creme fraiche.
Chop the lobster into bite sized pieces. Add the lobster meat, peas, pearl onions, and parsley to the sauce skillet.
Unfold the puff pastry onto a light floured surface and use a large circle cutter to cut 8 rounds of puff pastry. Move the rounds to a parchment paper baking sheet and bake until golden brown, and puffed, about 10 minutes.
Move the lobster mixture to oven safe ramekins or mini cast iron skillet and arrange on a baking sheet. Place one piece of puff pastry on each ramekin. Bake the pot pies for 10 minutes to heat the filling. Serve immediately.
Technique Tip: Cook the lobster meat yourself by getting some tails and claws in the shell and cooking them over a direct flame on the grill to add some delicious smoky flavor to compliment the creaminess of the pot pie.
Swap Option: King crab would be a nice substitution.