Preheat the broiler.
Place the breadcrumbs and mayonnaise in separate shallow dishes. Coat the fish fillets first in the mayonnaise and then in the breadcrumbs, shaking off any excess. Heat 2 tablespoons of the oil in a large skillet over medium-high heat until hot. Carefully place the fillets skin-side up in the pan and cook until golden brown, about 3 minutes per side, and then transfer to a broiler-safe plate.
Carefully drain the oil and wipe out the skillet with a paper towel. Replace the pan and heat the remaining oil over medium-high heat until hot. Cook the garlic and shallots, stirring frequently, 1 to 2 minutes. Stir in the dried herbs, mushrooms and scallions and cook 1 minute. Pour in the wine and half of the lime juice, season with salt and pepper and cook, stirring frequently, about 1 minute more. Melt in the butter until incorporated, and then remove the skillet from the heat.
Pour the mushroom mixture over the fish and top with the cheese. Place under the broiler until the cheese is melted, browned and bubbly, 3 to 5 minutes. Transfer to a serving plate and serve immediately, squeezing the remaining lime juice over the fish, if desired.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.