Cook the pasta as directed until al dente, reserving about 1/4 cup of pasta water. Strain and set aside, coating with olive oil to avoid sticking.
While the pasta cooks, prepare the salmon by patting dry and seasoning the flesh with salt, pepper, and juice of half a lemon. Heat the olive oil over medium heat in a pan. Once the oil is shimmering, add the salmon, flesh side down. Cook for 3-4 minutes to allow to crisp. Carefully flip and cook on the other side to allow to cook through. Remove from the pan and rest the salmon for a few minutes before flaking and setting aside.
Using the same pan set to medium heat, deglaze the pan with white wine by adding the wine and scraping up any bits stuck to the pan. Discard to clean out the pan.
Add 1 tbsp of ghee to the pan and allow to melt before adding the garlic. Saute for 3-4 minutes, and add the spinach, sauteeing until wilted.
Reduce the heat and add the cooked pasta and salmon to the pan. Toss to combine and add the lemon juice, 1 tbsp of ghee, and salt and pepper. Stir to combine, adding a bit of pasta water.
Serve the pasta in bowls and top with lemon zest and parsley.