Method
1. Add milk, cake flour and butter to a clean large saucepan and heat until boiling over medium heat
2. Whisk quickly until thick - approx 2 min
3. Add cheddar cheese and blue cheese, stir until melted then set aside
4. Add cornstarch and salt & pepper to a clean large mixing bowl and coat the prawns and white fish in the cornflour mixture
5. Add fennel bulb, green peppercorns, leek, dill, fresh parsley and salt to a clean food processor bowl
6. Blend until all ingredients are fine chopped, scraping down the sides as needed
7. Transfer blended leek and fennel mixture to the bottom of glass baking dish
8. Mix in gently prawns and whitefish filet
9. Add peas and cover with half of cheese mixture
10. Spread loosely and layer with potato
11. Spread second half of the cheese mixture
12. Sprinkle with cheddar cheese
13. Bake until light golden - 30 min, 220°C / 430°F
14. Reduce the temperature to 180°C / 355°F and bake until cooked through - 30 min
15. Let cool
16. Serve