Take the salmon out of the fridge 15-30 minutes prior to starting the recipe if possible. Cut it into 4 pieces. Pat each piece dry and season with the garlic powder and some salt & pepper.
Add the butter and olive oil to a skillet over medium-high heat. When it's hot, add the salmon. Cook for 3-4 minutes/side or until lightly browned. Do not overcook the fish; it shouldn't be cooked fully yet. Transfer the salmon to a plate.
To the skillet, add the onions and sauté for about 5 minutes or until softened and lightly golden.
Add the chicken broth, lemon juice, and the Boursin to the skillet. Stir until you've got a smooth sauce. Let it bubble for about 4-5 minutes, then stir in the chopped parsley.
And the salmon back into the skillet. Cook for another 3-5 minutes or so (I recommend turning the heat down) or until it's cooked through and it flakes easily with a fork and the sauce has thickened up some more.
Season with salt and pepper if needed and serve immediately.