Season salmon fillets with salt and pepper on both sides.
Melt 2 tablespoons of butter in a small saucepan over medium heat. Stir in lemon slices and minced garlic, cook for 2-3 minutes, until fragrant.
Place salmon fillets in a large baking dish. Brush the fillets with the garlic-lemon butter.
Bake in the preheated oven for 10-12 minutes, or until the salmon is cooked through.
In the meantime, prepare the vegetables. Place the trimmed asparagus and whole cherry tomatoes in a separate baking dish. Drizzle with olive oil and season with salt and pepper.
Remove the salmon from the oven and set aside. Place the vegetables in the oven and bake for 10-15 minutes, or until tender and slightly charred (or roast the vegetables in the oven at the same time as the salmon).
While the asparagus and cherry tomatoes are cooking, melt the remaining 2 tablespoons of butter in a small saucepan.
Serve the baked salmon fillets with the roasted asparagus and cherry tomatoes, topped with the melted butter. Sprinkle with chopped parsley, if desired.