Preheat the oven to 375°F (190°C) and line a baking sheet with aluminum foil or parchment paper. Place the salmon fillets skin-side down on the prepared baking sheet.
In a small bowl, combine the melted Irish butter, lemon juice, salt, and thyme. Use a basting brush or spoon to evenly spread this mixture over the top of each salmon fillet, ensuring the surface is coated.
2 fillets salmon fillets
Place the baking sheet in the oven and bake the salmon for about 12-15 minutes. Look for the fish to turn opaque and flake easily with a fork. The top should have a slight golden hue and smell fragrant of lemon and herbs.
Once cooked through, remove the salmon from the oven and spoon a little extra melted butter over the top if desired. Let it rest for a minute to allow flavors to settle.
2 fillets salmon fillets
Arrange the salmon fillets on plates, optionally garnish with additional thyme or lemon slices, and serve immediately to showcase the tender, flaky texture and bright, herby flavor.