Preheat oven to 400 degrees. Toss potatoes with 2 tablespoons olive oil, salt and pepper to taste, garlic powder, and 2 teaspoons Italian herb blend. Arrange on a large sheet pan and bake in preheated oven for 10 minutes.
Arrange salmon fillets and asparagus on the sheet pan. Whisk together melted butter, honey, dijon mustard, and 1/2 teaspoon remaining Italian herb blend. Brush onto salmon fillets.
Drizzle asparagus with remaining 1 tablespoon olive oil, season with salt and pepper to taste and place lemon slices between the asparagus spears.
Bake for 15 minutes until asparagus and potatoes are fork-tender and salmon is cooked through. Serve immediately.