Remove the salmon from the refrigerator and let it stand at room temperature for 10 minutes. Heat the oven to 375 degrees F. Line a large baking sheet pan with aluminum foil.
Add butter, herbs, garlic, salt, and pepper to a medium mixing bowl and mix together. The butter mixture can also be melted in a saucepan if needed for spreading.
Coat the foil with baking spray, then place the salmon on top. Add the herb butter mixture over the salmon fillet. Top with rosemary sprigs and lemon slices.
Gently tent the salmon with foil and bake for about 18-20 minutes. At the 18-20 minute mark, broil for 2 minutes to brown the top, watching carefully so it does not burn.
Cut into portions and serve with fresh greens.
Notes
If using vegan butter, ghee can be substituted.
Keyword baked salmon, herb butter salmon, lemon herb baked salmon, lemon salmon, whole salmon fillet