Prepare the filling by mixing the drained tuna, chopped parsley, diced onion, and capers in a small bowl. Season lightly with salt and pepper.

Heat about 1 inch of vegetable oil in a large skillet over medium-high heat until it reaches 350°F (175°C).

Lay out a sheet of brik pastry on a flat plate. If using phyllo, layer two sheets together to prevent tearing.

Spread a thin layer of harissa paste in the center of the pastry.

Place a quarter of the tuna mixture on top of the harissa, shaping it into a circle with a small well in the center.

Carefully crack an egg into the well of the tuna mixture.

Fold the pastry over the filling to form a triangle or half-moon shape, pressing the edges slightly to seal.

Immediately and carefully slide the brik into the hot oil. Do not overcrowd the pan; cook one or two at a time.

Fry for about 1 to 2 minutes per side until the pastry is golden brown and crispy, but the yolk inside remains slightly runny.

Remove with a slotted spoon, drain on paper towels, and serve immediately with fresh lemon wedges.