Sole Gascogne

Ingredients

• 2 tablespoons butter
• 1 teaspoon spring onions, finely chopped
• 1/2 teaspoon mild French mustard
• 1 teaspoon parsley, finely chopped
• 1 tablespoon tomato paste
• 2 tablespoons tarragon vinegar
• 1/2 cup sweet white wine
• Salt and black pepper
• 1 garlic clove, crushed
• 2 whole sole (4 whole fillets)
• Salt and cayenne pepper
• 1 tablespoon chopped chives
• 1 tablespoon chopped parsley
• 1/4 cup butter, melted
• 1/2 cup mushrooms
• 1/4 lemon, juiced, plus a little for the mushroom mixture
• Salt and black pepper
• 1 egg yolk
• 1/2 cup bread crumbs
• 2 tablespoons sweet white wine
• 1/3 cup gruyere cheese
• Paprika, to garnish