Preheat the oven to 350ºF (175ºC) and line a baking sheet with parchment paper.
Combine the walnuts, green onion, salt and Italian seasoning. Add the lemon juice and 1/3 of the oil and stir to mix.
Rub another 1/3 of the oil over all sides of the salmon fillets and place the salmon on the prepared baking sheet, skin side down. Spoon the walnut mixture on the top side of the fillets and gently press it down with the back of the spoon so the walnut mixture stays in place.
Toss the asparagus in the remaining oil and season with sea salt to taste. Place the seasoned asparagus in an even layer on the baking sheet with the salmon.
Bake for 12 to 15 minutes or until the salmon is cooked through and flakes easily and asparagus is tender. Divide between plates and enjoy!
