Preheat the oven to 180°C.
Heat oil in a frying pan and fry the onion and garlic for 4-6 minutes until softened.
Add the fish and shrimp, pour in the wine, and bring to a boil.
Simmer for 2-3 minutes, then stir in lime juice, zest, crème fraîche, parsley, and mustard.
Season with salt and pepper and simmer for another 2-3 minutes.
Divide the mixture into four ramekins and sprinkle with chopped tomatoes.
Scrunch filo pastry sheets over each ramekin and brush generously with melted butter.
Bake on a tray for 10-12 minutes until the pastry is crisp and golden.
Serve the pies with a portion of baby salad leaves.