Place 4 - 6oz flounder fillets on a lightly oiled baking dish. Melt 1/4 c. butter. Brush the tops of the fillets with 1 tbsp of melted butter. In a small bowl, combine 1 c. panko bread crumbs, 2/3 c. grated Parmigiano Reggiano cheese, 1/2 tsp kosher salt, cracked ground black pepper to taste, and 1 tsp thyme. Add the rest of the melted butter to the crumb mixture and mix it until the crumb mixture becomes buttery, crumbly, and golden in color. Sprinkle the crumb mixture over the fillets and lightly press the crumb mixture down into the fillets. Bake the fish for 12-15 minutes, or until the fish is opaque, flakes easily with a fork.