I am so glad I came across this very popular Peruvian hand held food called causa. I have loosely it translated it as a Potato Sandwich. The true recipe is spicier and includes mayonnaise. I just really took the idea and came up with Causa Joanna. The thing that amazed me was how easy it was to assemble. You will need what is called a round stainless steel cutter about 3.5 inches across and 2 inches down (available from Amazon) or something similar and you line it with saran wrap/clingfilm. The mashed potato should be smooth and fairly stiff so that it holds together well. Basically, there are four layers – potato, tuna, avocado and potato again to finish. It is a versatile dish served cold so suitable for a lunch box, a picnic or makes a meal in itself with a salad. Next time I have friends over for cocktails I will be serving tiny causa’s as canapes (and they can all be made in advance).
12 oz. mashing potatoes
Zest of half a lemon
1 x 6.7 oz.jar tuna fillets in olive oil (Tonnino brand is good)
1 avocado – mashed up
1 tbsp. Lemon juice
Peel and cook the potatoes then mash with 3 tbsp. of oil from the tuna jar (otherwise use regular olive oil). After that add the lemon zest and keep mashing so it is evenly distributed. Taste and season with salt and freshly ground black pepper if needed
Flake the tuna fillets with the remaining oil in the jar.
Mash the avocado with the lemon juice.
Layer the clingfilm lined stainless steel cutter starting with the potato and pack it down (each layer will need approx. 1 tbsp of each ingredient), followed by the tuna then the avocado and finished with another layer of potato.
Gently pull the sandwich out of the cutter using the clingfilm to pull on so that the bottom potato layer is on the top and keep in the clingfilm until needed – if not straight away, store in the fridge.