Peel and wash the potatoes and cut into small cubes approx. 1 cm in size. Blanch in boiling salted water for about 2-3 minutes, then drain and drain.
Wash the asparagus, peel the lower third, cut off the ends and cut into pieces approx. 3 cm long. Blanch in boiling salted water for 2-3 minutes, then drain and drain.
Clean and wash the spring onions, shake dry and cut across into 1 cm long pieces.
Heat 2 tablespoons of olive oil in a large pan, add spring onions and potatoes and stir-fry for 3-4 minutes. Whisk eggs in a bowl and season with salt, pepper and cayenne pepper. Add the asparagus and parsley to the potato and onion mixture. Brush an ovenproof dish (30 cm x 20 cm) with the remaining olive oil and pour in approx. 1/3 of the egg mixture. Add the vegetable mixture and fill up with the remaining egg mixture.
Bake in a preheated oven at 220 ° C for about 20 minutes.
Let cool a little, then loosen the edges with a sharp knife. Cut the tortilla into 2-3 cm cubes, insert a toothpick into each and arrange on a plate.