If fish filets are more than ½-inch thick, heat oven to 400˚F. If thinner, heat broiler on high.
Pat fish dry and cut into single portion-sized pieces if necessary.
Arrange with space between each piece on nonstick sheet pan or
sheet pan lined with parchment or foil. Sprinkle with salt and pepper.
Place one or two rosemary sprigs on each piece of fish, then layer lemon slices on top of rosemary. Add light drizzle of olive oil to each slice. Scatter olives in pan.
If fish filets are thicker than ½-inch, position rack in center of oven and roast for 6–8 minutes, until nearly opaque in center.
Move rack to top, turn on broiler and broil briefly until lemon slices
brown around edges.
If filets are thinner, start them on top rack under broiler. Cook,
watching closely, 3–4 minutes until opaque in center. Serves 4–6.