In a small bowl, flake the drained tuna and mix it with the chopped parsley, capers, and diced onion.

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

Place a sheet of brik pastry on a flat plate. Spread a thin layer of harissa in the center, then top with a quarter of the tuna mixture, shaping it into a ring to create a well in the middle.

Carefully crack an egg into the center of the tuna ring. Fold the pastry in half over the filling to form a triangle or semi-circle.

Immediately slide the brik into the hot oil. Fry for 1 to 2 minutes on each side until the pastry is golden brown and crispy, but the yolk is still slightly runny.

Remove from the oil and drain on paper towels. Serve hot with fresh lemon wedges.