How to do it…

1. Preheat oven to 450F/230C
2. Get out a casserole dish. I use a Le Creuset 12” x 9” that’s around 2” deep. You want the fish to be mostly covered in the sauce and have room for your potatoes on top. Not mounds of fish in a shallow pool of sauce and your potatoes fill in the gaps.
3. Now boil your potatoes in salted water. If you’d like, you can add the eggs a couple of minutes into the boiling time so they cook to hard-boiled, which should take 8-10 minutes. If you do the eggs and taters together, be careful when you add the egg to the water, you don’t want it cracking! Gulk.
4. Drain the potatoes and remove the eggs. Run cold water over the eggs so you can handle them and then peel and quarter them. You’ll come back to the eggs, but mash your potatoes using some salt and pepper and olive oil, milk or cream (however you do your mash) to flavor.
5. Right! That’s done, onward to the sauce. Drizzle a bit of olive oil into the bottom of a skillet and fry the onion and carrot for a few minutes, until they begin softening. Don’t do this too fast, you don’t want them to burn. Add the double cream and bring it nearly to boil. Take it off the heat and throw in the cheese, lemon and mustard.
6. Grab your casserole dish and put in the fillets and sprinkle the shrimp and egg quarters around. Pour the cream sauce on top. Spread your mashed potatoes on top of the fish and sauce.
7. I put this on a baking sheet in case the sauce bubbles up and around seeing as I don’t want that baked-on-burnt-on gunk at the bottom of my oven. Slide your dish on its tray into the oven and cook for 25-30 minutes (the potatoes and bubbly sauce should just start to brown). Take it out, let it settle for a few minutes, dish it up and gobble it down! If you and your family/guests are hungry, like seriously hungry, this serves four. But you could push it to six with some yummy veg and bread served with.