Preheat the oven to 200oc/400of/gas mark 6 and bring a large pan of salted water to the boil.
Peel the potatoes and cut into 2cm chunks.
Once the water is boiling, add your potatoes to cook for around 12 minutes until soft.
Get a deep baking tray or earthenware dish.
Peel the carrot.
Grate the celery, carrot and cheddar cheese all into the baking tray.
Grate the lemon zest.
Finely chop or grate the chili and add these to the baking tray.
Cut the salmon and trout into bite sizes and add to the tray with prawns.
Squeeze juice of lemon, drizzle with the olive oil and add a pinch of salt.
Add the spinach and tomatoes now.
Drain and mash the potatoes and place evenly over the ingredients in the tray.
Place the pie in the preheated oven for approximately 40 minutes.