Preheat oven to 400 degrees Fahrenheit. Trim at least 1 inch off the ends of the asparagus stalks. Set aside.
Make the herb butter: In a medium bowl, combine the softened butter, lemon zest, lemon juice, minced basil, minced rosemary, minced garlic, kosher salt, and pepper. Use a spoon or mini spatula to mix until combined. Set aside.
In a large bowl, toss the potatoes with one tablespoon of olive oil, parmesan, onion powder, garlic powder, ½ teaspoon of kosher salt, and cracked pepper. Toss to combine.
Dump the potatoes onto a sheet pan and roast for 15 minutes. Meanwhile, transfer the asparagus to the same bowl and toss with a teaspoon of olive oil and kosher salt. Set aside.
Heat a large nonstick skillet over medium-high heat. Add a drizzle of olive oil to the skillet. Season the top of each salmon fillet with kosher salt and pepper.
Sear the salmon fillets, skin side up, for 3 minutes. Carefully flip the fillets over and sear for 1 more minute.
Remove the sheet pan from the oven and use a spatula to scoot the potatoes to the left side of the pan. Arrange the salmon fillets in the center. On the left side, arrange the asparagus.
Place the sheet pan in the oven and roast for 10 to 15 minutes. Carefully, remove the sheet pan from the oven and top each salmon fillet plus the asparagus with 1 ½ teaspoons of herb butter.
Place the sheet pan back in the oven for 5 minutes.
Remove the salmon from the oven and immediately top with more butter. Serve warm!