Cut the onions into rings and the tomatoes into cubes. Then set aside and prepare the marinade.
To do this, put the yoghurt in a bowl, add 2 - 3 splashes of olive oil and stir in the pine nuts, roughly chopped. Do not season too strongly with pepper and salt.
Place the salmon side skin down on a baking sheet lined with aluminum foil and cover first with half of the onions, then the tomatoes and finally with the rest of the onions. Both can also be mixed and applied beforehand. Then apply the yoghurt marinade and cover the entire tray with aluminum foil.
Put in the oven for 20 minutes at 180 - 200 ° C (convection). After these 20 minutes, remove the aluminum foil and leave it in the oven for another 20 minutes at the same temperature.