Ingredients:
- 1 pound (450g) white fish fillets (such as cod or haddock)
- 1 cup (150g) frozen peas
- 1 medium carrot, diced (about 1/2 cup or 75g)
- 1 cup (150g) diced potatoes
- 2 tablespoons (30g) unsalted butter
- 2 tablespoons (15g) all-purpose flour
- 1 cup (240ml) milk
- 1 teaspoon Dijon mustard
- Salt and pepper to taste
- 1 package (14 oz or 400g) puff pastry, thawed
- 1 egg, beaten (for egg wash)
Instructions:
- In a medium saucepan, melt the butter over medium heat.
- Add the diced carrot and potato, sauté for approximately 5 minutes until starting to soften.
- Add the flour and whisk for 1-2 minutes until lightly browned.
- Gradually whisk in the milk, continuing to stir until the sauce thickens (about 3-5 minutes).
- Stir in the Dijon mustard, salt, and pepper.
- Add the fish and peas; gently fold until combined.
- Preheat the oven to 400°F (200°C).
- Roll out the puff pastry on a lightly floured surface to fit your baking dish.
- Transfer the filling to the baking dish, smoothing it out evenly.
- Place the rolled pastry over the filling, pressing the edges to seal.
- Cut a few slits in the pastry for steam to escape.
- Brush the top with beaten egg for a golden finish.
- Place in the preheated oven and bake for 25-30 minutes, until the pastry is golden brown and puffed.
- Check that the internal temperature of the filling reaches 165°F (74°C).
- Allow cooling for a few minutes before slicing and serving.