Before getting down to work with the salmon, we must prepare a good (and delicious) bed for it to rest on. For this reason, we will cut the potatoes into slices -half a centimeter thick-, the pepper and spring onion in julienne strips, as well as the tomato into thin slices. We will distribute all these vegetables on the oven tray, and we will season and add a little olive oil, a little water and a little white wine.
With the oven at 190º, we will bake the vegetables for 20 minutes until the potatoes take on color and the rest of the vegetables have been well poached. Sprinkle that coat with black pepper and place the seasoned salmon loin on top. Next to this, we will add some green onion rings, distributing them on top.
We will let the fish cook for 10 minutes (we cannot leave it longer since we can cook it too much, losing its juice and drying out its meat). The trick? Flatten it lightly with a fork and see if the fish flakes separate (it will mean that it is ready).
We can serve directly from the same baking dish to avoid dirtying more trays.