Bring a large pot of salted water to a boil. Add the fettuccine noodles and cook until al dente, about 8-10 minutes. Reserve ⅓ cup of the pasta water before draining.

Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Season the salmon with salt and pepper, then sear skin-side down for about 5 minutes. Flip and cook for an additional 4-5 minutes until cooked through.

In the same skillet, reduce heat to medium and melt 2 tablespoons of butter. Sauté 3 cloves of minced garlic for 30 seconds, add 1 finely chopped shallot, and cook until translucent, about 2 minutes. Stir in ⅓ cup of chopped sun-dried tomatoes.

Pour in the reserved pasta water, and allow to simmer for about 2-3 minutes. Add 1 cup of heavy cream and ½ cup of half-and-half, mixing well. Season with salt and pepper. Simmer for another 3-5 minutes until thickened.

Incorporate 2 cups of fresh baby spinach and stir until wilted. Gradually mix in ½ cup of grated Parmesan until melted and smooth.

Add the cooked fettuccine to the sauce, tossing gently to coat. Adjust thickness with reserved pasta water if necessary.

Garnish with freshly chopped parsley and a squeeze of lemon juice before serving.