Preheat oven to 350 degrees.
Bring a pot of water to boil, place asparagus in pot and boil for 5 minutes until crisp-tender. Drain and set aside.
Spread walnuts out in a single layer on a baking sheet. Bake for 8-10 minutes in preheated oven until toasted. Watch the nuts carefully to make sure they do not burn.
Place salmon fillets in a greased baking pan. Salt and pepper each fillet to taste.
Broil the fillets 6-7 minutes on each side until they flake easily with a fork.
Combine the lettuce, asparagus and walnuts in a large bowl.
While the salmon is cooking, whisk together the olive oil, lemon juice, tarragon, honey, Dijon mustard, ½ tsp salt and ¼ tsp pepper to make the salad dressing.
Toss the salad ingredients with the dressing, reserving a small amount of dressing to pour over the salmon.
Serve the salad on a plate topped with a salmon fillet. Pour a little dressing over the salmon before serving.