Bring a large pot of water to a boil. Add salt and pasta and follow package instructions until is al dente; and drain. Reserve about 4 tbsp.
Season salmon with salt and pepper. In a large skillet, over medium-high heat, add olive oil, and sear salmon for about 5 minutes on each side. Then remove and set aside on a plate. If you forgot to remove the skin, now is the time to remove it. It should come away from the fillet quite easily.
Spinach Dill Sauce: On medium heat, add the 2 tbsp olive oil to the skillet, then add leeks and sauté for about 4 minutes until softened. Add garlic, spinach, dill, lemon juice and sauté for about one minute. Season with salt and pepper. Then add chicken broth and boil over medium-high heat for about 4-5 minutes. Then add to a food processor or blender and blend until smooth. If using sour cream, add to the food processor or blender and blend one last time. **You can make this ahead of time and set aside.
Sauté: In the same skillet, you will need to add about 1 tbsp olive oil, add the asparagus and sauté for about 5 minutes. Then add the sun-dried tomatoes, pasta, sauce, and salmon chunks. Toss gently until well coated. Add the reserved pasta water if needed. Check for seasoning, add if needed.
Garnish with Parmesan cheese and fresh dill.
