Prepare salmon fillet — remove skin, butterfly, and flatten evenly.
Mix filling — combine cream cheese, garlic, spinach, herbs, lemon juice, and zest.
Spread filling evenly over salmon and roll tightly using plastic wrap.
Chill for 30 minutes to firm up before slicing.
Slice into 1-inch rounds and place on a parchment-lined baking sheet.
Brush with olive oil, season, and bake at 375°F for 15–18 minutes.
Broil 2 minutes for golden tops, then rest before serving.