Pour the tuna into a sieve and drain well. Peel and finely chop the onions. Put tuna, eggs, onions and 75 g breadcrumbs in a bowl and knead well with your hands.
Season vigorously with salt and pepper. Form approx. 30 mini rissoles with wet hands. Turn in 25 g breadcrumbs. Heat 2-3 portions of oil in a frying pan. Fry the meatballs in 2-3 portions on each side over medium heat for about 2 minutes.
Remove and put aside. In the meantime mix mayonnaise and asia sauce. Wash and drain the tomatoes. Wash the parsley, shake dry and pluck the leaves from the stalks. Put silver onions, tomatoes, gherkins and parsley on skewers and put them into the meatballs.
Arrange on a plate garnished with some sauce and parsley leaf. Add the rest of the sauce in a small bowl.