Preheat your oven to 400°F (200°C).
Toss the Costco mixed vegetables (broccoli, cauliflower, sugar snap peas, and carrots) with the olive oil, half of the sea salt, and half of the black pepper on a baking sheet.
Roast the vegetables for 12-15 minutes until they are tender-crisp.
While the vegetables roast, finely chop the fresh parsley and thyme, then combine them in a small bowl with the lemon zest.
Season the salmon fillet with the remaining sea salt and black pepper, then brush the top surface with the Dijon mustard.
Press the herb and lemon zest mixture firmly onto the mustard-coated side of the salmon to create a crust.
Move the vegetables to one side of the baking sheet and place the salmon on the other side.
Return the pan to the oven and bake for another 10-12 minutes until the salmon is opaque and flakes easily with a fork.
Transfer the roasted vegetables to a bowl, top with the herb-crusted salmon, and drizzle with fresh lemon juice before serving.