Prepare the ingredients: slice the mushrooms. Spiralize the zucchini. Alternately, you can dice the zucchini if you do not have a spiralizer. Set aside. Season the salmon with salt and pepper.
Heat a large non-stick skillet over medium high heat. It is very important that the pan is very hot in order to brown the salmon properly!
Once the pan is hot, add the salmon skin side up. If you have skinless salmon, place the seasoned side down. Leave undisturbed for 5 to 6 minutes, or until the skin is browned and the fat from the salmon begins to render. Turn the salmon and brown the sides for 1 to 2 minutes. Lastly, turn the salmon skin side down for the remaining 2 to 3 minutes to finish cooking. To check for doneness, use a fork to gently pull at the thickest portion of the salmon. It should easily flake and not appear raw underneath. Transfer the salmon to a plate and cover with tin foil to keep warm.
Reduce the heat to medium heat. Add the mushrooms to the same pan you used to cook the salmon and sprinkle with salt and pepper. Cook 2 to 3 minutes, or until the liquid escapes. Set aside in a small bowl.
In the same pan, cook the zucchini noodles for 3 to 4 minutes, or until just slightly soft (al dente). Be careful not to overcook the zucchini (you don't want soggy noodles!). Remove from heat and drain the liquid. Toss the noodles with two-thirds of the pesto.
Divide the pesto zucchini among two plates. Top with the mushrooms. Layer the salmon on top and spoon the remaining pesto on top of the salmon. Garnish with additional Parmesan or fresh herbs, if desired. Enjoy!