Preheat oven to 400°F. Tear four 12-inch sheets of heavy-duty foil and arrange them on your counter. If using regular foil, double it up for each packet.

Place potatoes in a microwave-safe bowl with 1 tablespoon water. Cover and microwave on high for 4 minutes until just tender when pierced with a knife. This ensures they finish cooking with the salmon instead of staying crunchy.

In a small bowl, whisk together melted butter, garlic, lemon zest, lemon juice, and chopped dill. Set aside.

Divide par-cooked potatoes among the four foil sheets, placing them in the center. Toss with 1 tablespoon olive oil and half the salt. Top with asparagus, then place a salmon fillet on each bed of vegetables. Drizzle remaining olive oil over salmon and season everything with remaining salt and pepper.

Spoon the lemon-garlic butter evenly over each salmon fillet, letting some drip onto the vegetables. Fold the foil over and crimp edges tightly to seal, leaving a little room inside for steam to circulate.

Arrange packets on a rimmed baking sheet and bake for 15-18 minutes. The salmon is done when it flakes easily with a fork and reaches 145°F internally. Open a packet carefully - watch the steam - and check; if your fillets are thick, give them another 2-3 minutes.

Transfer contents of each packet to shallow bowls or serve directly in the foil. Spoon any accumulated juices over the top and garnish with fresh dill. Serve with lemon wedges on the side.