Preheat oven to 350 degrees F.
Begin by baking the puff pastry "cups". Lay the thawed puff pastry sheets on a lightly floured, cool surface. Using a 4 1/2-inch round cutter, cut out 4 circles. Set them on a parchment-lined sheet tray. Lightly score the tops of the puff pastry with a 4-inch round cutter. This will help remove the top of the puff pastry after it is cooked, to create a "cup". Beat egg then use a pastry brush to brush the tops. Season with sea salt and place into the preheated oven. Bake in oven for 12 to 15 minutes until golden and crispy. Once cooled, cut the "tops" of the "cups" and lay bases out on plates.
While the "cups" are baking, make the beurre blanc. In a large, clean saucepan add shallots, white wine, white wine vinegar, fresh thyme and bay leaves. Simmer until reduced by half then season well with salt and plenty of freshly ground black pepper. Strain the sauce, place back over low heat and reduce. Add the cream and stir. Add butter several cubes at a time while stirring until the sauce thickens. Keep warm and set aside.
Blanch the peas and carrots. Set a pot of salted water over high heat and bring to a boil. Add carrots first to give them a head start then add the peas briefly to cook the vegetables until tender but still firm - about 2 minutes. Drain and set aside.
Clean scallops and season with kosher salt and freshly ground black pepper. Set a large saute pan over high heat and add olive oil. Once heated, add scallops and cook undisturbed for 2 to 3 minutes on each side until well browned. Set aside on paper towels.
Increase the heat and add the chanterelles and saute. Add carrots and peas to the pan and saute for 1 to 2 minutes until heated through. Add the scallops back to the pan, on top of the vegetables, to heat through.
To serve, portion out amongst the pastry cups. Top with a matching pastry lid - rest it just off center so you can see the filling and garnish with chives and a stem of fresh parsley. Serve immediately.