Prepare the salmon – season the salmon filets on both sides with salt and pepper.
In a wide, large skillet over medium heat, warm up the olive oil and then add and melt the butter.
Once the butter is melted, add the diced onion and sauté for 1 - 2 minutes, and then add the minced garlic and sauté until fragrant, for 1 minute only, stirring constantly (do not burn the garlic).
Add the salmon filets, skin-side down if you have skinned filets. Sauté the salmon for 2-3 minutes, then flip over and cook for 1-2 minutes on the other side. You do NOT need to brown the salmon in this recipe. If you're concerned, a safe internal temperature of 145°F on an instant-read thermometer at the thickest part of the salmon means that the salmon is well-done.
Remove the salmon from the skillet and place on a platter. Cover and tent the filets with aluminum foil and allow them to rest and keep warm while preparing the sauce.
Using the same olive oil and butter base, add the sun-dried tomatoes, minus the oil. Then add the cherry tomatoes and cook for about 4 - 5 minutes for the juices to combine.
Add the baby spinach leaves. Continually stir while they quickly wilt, shrink, and darken (see this happen in the video).
Add the cream and heat it up so it melts the cheese in the next step.
Add the Parmesan cheese and cook on low heat for a minute or two to thoroughly melt the cheese and thicken the sauce, stirring constantly.
Add the Italian parsley and basil and blend well.
Add a few squeezes of fresh lemon juice.
Place the salmon back into the pan with all of the sauce. Spoon the warm sauce over the salmon filets and re-heat for about 2 minutes. Do not overcook.
Garnish with more minced Italian parsley and/or basil.
Serve immediately with some delicious garlic bread/rolls to mop up the sauce along with some delicious side dishes.
BUON APPETITO!!