Boil potatoes until tender (ca 30 minutes)

Peel potatoes and mash them

Add tuna and the egg, mix well

Add grated parmesan

Now add as much bread crumbs you need to make the mix solid enough

Add seasonings (salt, pepper, parsley, chives) and mix

Make it rest in the fridge for 15 minutes

Shape the mix to fit the loaf pan, then roll it into the bread crumbles you have left

Put into the loaf pan and spread some olive oil all over it

Cook in parchment paper at 200°C for 30 minutes

Serve with mayonnaise to taste