Remove the skin from the vegetable onions and chop very finely. Drain tuna in a colander, drain and chop finely. Clean parsley, rinse and shake dry. Pluck off the leaves and also chop finely.
Mix parsley, diced onion, tuna, juice of one lemon and harissa and season heartily with salt and freshly ground pepper.
Spread 1 spring roll sheet on a floured surface.
In the center of the pastry sheet, shape a quarter of the tuna mixture, press in an indentation and place 1 egg yolk inside. Lightly whisk egg whites. Brush edges of dough with a tiny bit of egg white, fold dough over filling and press firmly. Do the same with the remaining 3 sheets of dough.
Put oil in a frying pan about two fingers wide and heat. Place dumplings in and fry in about 5 min until golden brown, turning once to the other side. Lift out tuna pockets and drain a little on kitchen roll.
Our tip: As an alternative to fresh herbs, you can also use frozen ones – they also stand out for their fresh taste!