How to make it
Steam the baking potato until cooked, peel off skin and whisk into mash with a fork.
Add chopped carrots, parsley and marinade into mash, mix well, then wrap loaf in cling film and chill to a thick consistency in the refrigerator for 30 minutes.
Remove loaf from refrigerator, add tuna fish and form into circular patties. Fry with olive oil over medium heat until golden and heated through to serve.