In a large pot of boiling, salted water, cook the linguine until almost done, about 12 minutes. Drain.
In a medium saucepan, combine the broth, sherry, soy sauce, ginger, scallions, and salt. Bring to a simmer and continue simmering, covered, for 5 minutes. Add the mushrooms and the salmon to the broth and simmer, covered, until the fish is just cooked through, about 6 minutes for a 3/4-inch-thick fillet. Remove the salmon from the broth.
Stir the pasta, spinach, and bean sprouts into the broth. Cover and simmer until the pasta is done, about 3 minutes. Put the linguine and vegetables into serving bowls. Top with the salmon and ladle the ginger broth over the top.
Fish Alternatives: The sherry, soy sauce, and ginger in the broth would also complement meaty tuna steaks. Try them instead of the salmon.
Wine Recommendation: A full-bodied but acidic white wine will be well-suited to the deep, earthy flavors of the whole-wheat noodles, salmon, and mushrooms. Tokay Pinot Gris from the Alsace in France or sémillon from Washington State are both good examples.