Creating Salmon and Asparagus Foil Packs with Garlic Butter Sauce is straightforward when you follow these steps:

1. Preheat the Oven or Grill: Preheat your oven to 400°F (200°C) or prepare your grill for medium-high heat.
2. Prepare Foil Sheets: Cut four large pieces of aluminum foil, about 12×18 inches each.
3. Arrange Asparagus: Place a handful of trimmed asparagus in the center of each foil sheet.
4. Add Salmon: Lay a salmon fillet on top of the asparagus in each pack.
5. Make Garlic Butter Sauce: In a small bowl, combine melted butter, minced garlic, paprika, salt, and pepper.
6. Drizzle Sauce: Pour the garlic butter mixture evenly over the salmon and asparagus.
7. Add Lemon Slices: Place a slice of lemon on top of each fillet.
8. Seal the Foil Packs: Fold the sides of the foil over the salmon and asparagus to seal tightly. Make sure there are no openings.
9. Cook: Place the prepared foil packs on the grill or in the preheated oven. Cook for 15-20 minutes, depending on the thickness of the salmon.
10. Check for Doneness: The salmon should be opaque and flake easily with a fork. The asparagus should be tender but still slightly crisp.
11. Carefully Unwrap Packs: Use caution when opening the foil packs, as steam will escape.
12. Garnish and Serve: Sprinkle with fresh parsley, if desired, before serving.

These steps will guide you in creating a delicious meal that is sure to impress.