First of all, peel the onions, cut in half and bake in a preheated 180 degree oven for 20-30 minutes (until soft).
While the onion is cooling, cut the herring, Apple, bell pepper and red onion into small cubes. Stir.
Carefully cut out the core of the baked onion, leave the walls 0.5 cm.
The core of the onion is well crushed with a knife and mixed with mayonnaise. I have mayonnaise with lemon juice.
Fill the resulting sauce with our herring mass.
In onion cups, lay out the filling, decorate with herbs.