How to Make It
Prepare pasta according to package directions, omitting salt and fat. Drain, reserving 3/4 cup cooking water. Set aside.
Heat 1 tablespoon of the oil in a large skillet over medium heat. Add asparagus, spring onions, and 1/2 teaspoon of the salt; cook, stirring occasionally, until asparagus is tender and onions are translucent, 8 to 10 minutes. Add wine, and increase heat to high; cook, stirring occasionally, until liquid is partially reduced, about 1 minute. Add stock and 1/4 cup of the reserved cooking water; bring mixture to a simmer and let sit, undisturbed, 1 minute. Stir in cooked pasta, parsley, heavy cream, butter, lemon zest, thyme, and mint. Remove from heat; add cooking water 1 tablespoon at a time until pasta is well coated and desired consistency is reached. Cover to keep warm.
Heat 1 tablespoon of the oil in a large skillet over medium-high. Sprinkle salmon evenly with pepper and remaining 1/2 teaspoon salt. Add salmon to skillet; cook until a thermometer inserted in thickest portion of fillet registers 120°F (for medium), 4 to 5 minutes per side, or until desired degree of doneness. Remove from heat. Flake salmon into large chunks.
Divide pasta mixture evenly among 6 bowls; top evenly with salmon pieces. If desired, drizzle evenly with remaining 1 tablespoon oil.