These Sri Lankan fish patties (පැටිස්) are much similar to empanadas or curry puffs but filled with spicy fish-potato filling. Fried until golden and flaky. So delicious!!
Into the food processor, add flour, salt, and sugar. Pulse a couple of times until they're mixed. Cut the butter into cubes and add to flour.
Run the food processor until all the butter is mixed with flour and there aren't any lumps of butter left. The mixture should look like fine sand or large flour grains. Do not run the food processor for too long as it can increase the temperature and melt your butter.
Add vinegar first. And then add cold water, little by little from the feed tube, while running the food processor on low. Stop the food processor when the mixture forms small lumps and gets thicker. If flour sticks together when you squeeze some, it means you have enough moisture in the dough.
Dump everything in the food processor onto the counter/pastry bench. Press them all together using your fingers, to make a large ball.
Divide into two, and roll it into two long cylinders, about 1.5 inches in diameter. Wrap both cylinders with plastic wrap. Put it into the fridge for 1 - 2 hours or until it gets hardened.
Peel and cut potatoes into large chunks. Boil them with 1/2 tsp salt (or half of the given amount if you're doubling or tripling the recipe). When you can easily pierce potatoes with a fork, turn off the heat and drain them immediately into a colander. Leave the potatoes in the colander to cool down and dry off of moisture.
Heat oil in a frying pan or a small wok. Add cinnamon and pandan leaves and let them fry for about 5 seconds. (be careful of splattering oil when you add pandan leaves)
Then add onion, garlic, green chilies, and curry leaves* with 1/2 tsp of salt. Saute until translucent.
Then add curry powder and turmeric powder. Mix well and saute about 30 seconds until you get the aroma of curry powder and onions turn yellow in color.
Add mackerel/tuna and mash it into small pieces with the back of your spoon (make sure not to add any liquid from the cans). Mix well with the onions and saute for about 1 min on medium heat until mackerel pieces coat well with the onion mixture.
Mash your potatoes until they are small chunks ( I usually press them with a large wooden spoon. You can use a masher or squeeze them by hand). Add the potatoes to the pan and saute well until everything is very well mixed.
Add black pepper, lime juice, and salt to your taste. The mixture should taste slightly acidic with a somewhat prominent lime flavor but it will balance out once you fried the patties.
Remove pandan leaves and cinnamon sticks from the mixture. Let the mixture cool completely before you assemble the patties.
Cut the refrigerated dough into roughly 35g discs.
Roll one disc into a flat round shape, roughly around 2mm thick. Using a round cookie cutter (a jar/bottle cap would also work), cut the dough into a perfectly round shape, roughly around 3 .5 - 4 inches in diameter.
Place about 3 tbsp of filling on one half of the round. Apply a little bit of water around the edge.
Fold one half over the other and press the edges together to seal. Press the tip of the fork over the seam to complete the seal.
Arrange patties in one layer on a plate. Refrigerate them for about 1/2 hour or until you're ready to fry them. Or store in the freezer (Check the description for freezing instructions.)
Heat oil in a deep sauce pan/wok/deep fryer. Keep the oil at medium temperature around 350F/175C (see notes). Make sure there's enough oil to fully submerge the patties. Add a few patties to hot oil. Fry until they are golden brown. Flip halfway through frying.
When patties are golden brown, take them out of the oil using a slotted spoon and transfer them to a paper towel-lined plate. If you want to keep them crispy for longer, let them rest on a cooling rack.