Note: I use Samosa spring roll pastry sheets which are 3x9 inches. If you are using egg roll wrappers that are 7x7 inches they need to be cut in half so they measure 3.5x7.
Set out the frozen spring roll pastry so it can thaw (around 30 minutes).
If using raw potatoes, peel & dice them, then boil them until just tender. Set aside to be used later. If using canned diced potatoes drain the water & set aside to be used later.
Drain the water from the tuna & place in a medium bowl. Chopped the parsley & cilantro together then add it to the tuna.
Mix the onions, olives, harissa, & spices together then add to the tuna. Add the olive oil to the tuna & stir until all the ingredients are well blended. Lastly, add the potatoes & carefully stir in so they do not break apart.
Note: Keep the wrappers under a damp towel so they do not dry out.
Put 2 tablespoons of the filling at the top of a pastry strip. Fold over into a triangle, then fold over again & again.
Lightly brush the end of the pastry strip with egg yolk & fold closed. (The egg yolk helps hold the strip together). Repeat the last 2 steps until all the filling is gone.
Heat the oil (canola or peanut) in a medium pan. Once hot add about 5 triangles to the oil. Fry until golden brown, turning once. Repeat until all the triangles are cooked.
Variation: Preheat the oven to 350 degrees & bake for 20-30 minutes. The pastries should be puffed & golden brown on both sides.