Bring large pot of water to a boil and cook asparagus for three minutes. Remove asparagus and drain under cold water, then chop. In a large pan, reduce heavy cream halfway then add smoked salmon. Meanwhile, cook pasta. Keep reducing. Whisk in <1/2 cup of butter. Add asparagus, scallions/chives, and allow to cook briefly. Drain pasta, then mix with cream sauce, parmesan, and pepper.