Preheat the oven to 170C/150C Fan/Gas 3 and butter 4 small cocotte dishes.
Pour the milk and cream into a saucepan with the bay leaf and peppercorns and bring to a simmer. Remove from the heat and set aside to "infuse" for 30 minutes.
Put the pan back onto the heat and bring the liquid back to a simmer, add the haddock and poach gently for 5 minutes, or until the fish flakes apart when pushed.
Remove the fish from the liquid and flake into a separate bowl.
Melt the butter in a separate saucepan, then add the flour and whisk together them together.
Strain the poaching liquid into a jug and measure out 300ml/10fl oz.
Gradually whisk the liquid into the butter and flour until smooth, then simmer gently for 2–3 minutes, or until thickened.
Pour most of the sauce over the fish, reserving a little for the top of each egg, and carefully fold to combine.
Divide the mixture between the moulds, then crack an egg on top of each.
Spoon over the reserved sauce, sprinkle over the Parmesan and then transfer to a deep roasting tin.
Pour in enough boiling water to come halfway up the sides of the dishes, then bake for 10–12 minutes, or until the whites are set and the yolks are still runny.
Garnish with the chopped chives and serve with hot buttered toast.