Variations on a theme

I thought this would be nice, but it was even nicer than I thought it was going to be!
Serves 2

1 small leek
1 small head cauliflower
2 hard-boiled eggs, chopped
2 "skinless, boneless" coley fillets
250 ml milk
2 tsp plain flour
1/4 tsp mustard powder
Salt and pepper to taste
About 30 g grated Cheddar cheese
100 g tagliatelli or other pasta

Cook the pasta according to the instructions on the packet. Separate the cauliflower head into florets and steam. Chop the leek, and cook in about 1/2 tbs olive oil (I added 2 tbs water from the pasta when it was hot). Thaw the fish until you can dice it, and chop the hard-boiled eggs. Whisk the flour, milk, mustard, salt and pepper together, and pour on to the leeks. Bring to the boil, stirring all the time. Add the fish and allow to cook for a minute or two. Then add the eggs and the drained pasta, and the cauliflower if there's room. If not, put the cauliflower into an ovenproof dish, and pour the rest of it over it. Stir well to mix. Top with grated cheese and bake in a moderately hot oven for 30 minutes.