Preheat the oven to 400 degrees Fahrenheit.

Lay the salmon filet on a parchment-lined large baking sheet or a large baking dish lightly sprayed with non-stick spray. Drizzle with avocado oil and use your hands to brush it over the surface of the salmon so that it’s lightly coated with oil. You can also use a silicone brush for this if you’d like. Sprinkle the filet with sea salt and garlic powder. Bake the salmon on the center rack of the oven for 10 minutes.

While the salmon is baking, prepare the topping. Heat avocado oil in a large non-stick skillet over medium heat. Add the chopped onion and sauté until softened, about 5 to 8 minutes.

Add in the sun-dried tomatoes and spinach and cover the skillet. Cook, stirring occasionally, until spinach has wilted.

Stir in the feta cheese and continue heating until the feta begins to melt.

Remove the salmon from the oven and transfer the spinach mixture on top of the salmon so that the full filet is covered with the mixture.

Bake salmon (again at 400 degrees) for another 8 to 10 minutes with the toppings on, or until the salmon is cooked through.

Salmon is considered fully cooked when it reaches an internal temperature of 145 degrees F. To verify the temperature, insert a meat thermometer into the thickest part of the fish and wait until the numbers stop moving. 

You can also tell salmon is fully cooked when it is opaque and fully pale pink with no bright pink areas. The exact baking time depends on the size of the salmon filets, so this is where a thermometer is your best friend.

Drizzle salmon with pesto sauce if desired. The pesto sauce isn’t necessary because there is already a lot of flavor, but I just love how it turns out with the pesto. You can also sprinkle freshly grated parmesan cheese on top of the filet.

Allow the salmon to rest for 10 minutes before slicing it into individual portions and serving.

Serve with your favorite side dishes, and enjoy!