1) Preheat oven to 450 degrees F. Preheat baking pan. In a small bowl, whisk together garlic, sesame oil, vinegar, and mustard. Place a single layer of asparagus stalks on a foil sheet large enough to make a foil pouch around the asparagus and salmon. Lay salmon piece, skin side down, on the asparagus layer. Brush oil mixture liberally over salmon. Add salt and pepper and drizzle a little olive oil on the exposed asparagus. Seal up the foil around the fish. Repeat the same process for the other pieces of salmon and place all sealed pouches on preheated pan.
2) The general rule is to bake fish 8 to 10 minutes for every inch of thickness. However, when my salmon is 1/4 inch thick, this recipe (with asparagus) takes about 8 minutes in the oven and 3 minutes under the broiler. Check the salmon a few minutes early. About 3-5 minutes before it's done, turn the broiler on. Open the foil enough so the top of the fish is exposed. Place the pan four inches from the heating element. Don't overcook it, but let it finish cooking under the broiler for a little charring. As soon as it starts charring, take it out of the oven so it doesn't dry out. When the fish starts to flake easily with a fork, it's done. Enjoy!