Lasagna with yolks

600 g salmon 15 ml oil (3 teaspoons) 2 carrots (medium diced) 2 celery ribs (big diced) 1 onion (medium diced preferably tender sweet white) salt (to taste)[...]

15 ml olive oil 1 medium white onion, finely diced 1 medium carrot , finely diced 1 large celery rib , finely diced 2 tomatoes , skinned, seeded, finely diced[...]