Heat the oven to 200 C and line a large sheet pan with parchment.
Toss the potatoes with 2 tablespoons olive oil, seasoning blend, garlic powder, salt, and pepper. Spread them cut side down and roast for 15 minutes.
Stir the potatoes and push them to the sides. Add asparagus and tomatoes. Drizzle with 1 tablespoon olive oil and a pinch of salt and pepper.
Whisk butter, honey, dijon, sriracha, lemon zest, lemon juice, and the seasoning blend. Pat the salmon dry and brush on the glaze.
Nestle the salmon on the pan. Roast 10 to 12 minutes until the fish flakes and the potatoes turn golden. Thick fillets may need a minute more.
Rest the tray 2 minutes. Squeeze fresh lemon over everything, scatter parsley, and serve warm.