Make the mushroom sauce. Heat the olive oil in a skillet on medium heat. Add the onions, cook for about 5 minutes until they begin to soften.
Add the mushrooms to the pan, and stir to combine with the onions. Add a pinch of salt. Cook until the mushrooms begin to “sweat” (give off liquid), then stir in the red wine along with the thyme.
Cook the mushrooms until the red wine is mostly absorbed, about 5 more minutes.
The mushrooms should be nice and tender now. Finish the sauce by adding the butter, stirring so it gradually melts in with the mushrooms. Add salt and pepper to taste. Cover and keep on very low heat to keep warm while you cook the salmon.
Start cooking the salmon by heating the canola oil in a skillet on medium-high.
When the pan is good and hot, add the salmon, skin side down. Sprinkle a little extra oil on top along w a touch of salt. Don’t touch the fish for about 4 minutes.
After searing the salmon on the skin side for 4 minutes, flip the fish with a spatula. Cook on the flesh side for another 2 to 3 minutes. Remove salmon from heat and let it rest for a few minutes covered loosely with foil. The fish should still be very moist and have a dark orange color inside.
Cut a portion of salmon for each person, and served topped with some mushroom sauce. Enjoy with a glass of red wine!