1. Combine parsley leaves, olive oil, lemon, garlic and salt in a blender. Pulse until chunky but well-combined. Adjust seasoning as needed.
2. Heat grill or grill pan on high heat.
3. Pat sardines dry with paper towel. Brush with olive oil and sprinkle with salt.
4. Grill sardines until cooked through with deep grill marks, about 4 minutes per side.
5. Serve sardines with gremolata spooned over top.
*Can use a cast iron pan in place of grill. Heat over high heat.