Preheat your oven to 425°F (220°C).

In a medium bowl, whisk together the freshly squeezed lemon juice, olive oil, minced garlic, and Dijon mustard to create a marinade.

Place the skinless salmon fillets in a baking dish and pour the marinade over the top. Season with black pepper and a pinch of salt. Let marinate for about 10 minutes.

Transfer the baking dish to the preheated oven and bake the salmon for 10–15 minutes until flaky.

Melt unsalted butter in a saucepan over low to medium heat.

Add the minced garlic to the melted butter and sauté for about 30 seconds until fragrant.

Stir in the heavy cream and bring to a gentle boil. Simmer for 2-3 minutes, thickening slightly.

Remove from heat and stir in remaining lemon juice and parsley. Adjust seasoning with salt and pepper.

Pour the creamy lemon butter sauce generously over each fillet and garnish with lemon slices before serving.