Gypsy peppers—which are long, pointy and mild and come in a variety of colors—are popular on the West Coast. If you can't find them, use red bell peppers. Amazing Seafood Recipes
In a small bowl, combine the vinegar and shallots and let stand for 5 minutes. Cut one of the lemon quarters into paper-thin slices. Finely chop the slices, including the rind, and add to the shallots along with the gypsy pepper, capers and the 1/4 cup olive oil. Squeeze the juice from the remaining lemon quarter into the relish and season with salt and pepper. Arrange the frisée on 4 plates and top with half of the lemon relish.
Brush the scallops with olive oil and season with salt and pepper. Grill or sear in a preheated grill pan, turning once, until the scallops are charred and cooked through, about 6 minutes. Arrange the scallops on the frisée, garnish with the remaining lemon relish and serve.