Make Gremolata Sauce. Add one tbsp of white wine (optional) to the Gremolata sauce and stir to combine. Set aside until needed.
grill the sardines
Place a grill pan over high heat (or use an outdoor grill). Clean the sardines. Using a small knife, gently rub the skin of the sardine until the scales are removed. Then cut open the belly of the fish using the same small knife. Run your thumb along the spine and push out the bloody guts. Rinse the sardines under cold running water. Drain well on a kitchen towel and tap dry. They need to be completely dry for the grilling. Drizzle the sardines with olive oil and gently place them on a hot grill or in a hot grill pan. Grill for 2 - 3 minutes on each side, depending on the size of the fish.
Serve the grilled sardines as soon as possible. Season with salt to taste and drizzle with Gremolata sauce. Add lemon wedges and enjoy.