Preheat oven to 375 F.

Bake the hazelnuts on a sheet pan until toasted, about 8-10 minutes. Transfer to a kitchen towel and rub until skins come off (it’s ok if some of the skin remains on the hazelnuts). Coarsely chop and set aside.

Place the watercress in a large bowl and toss with 2 tablespoons of the olive oil, salt, and 1/4 teaspoon pepper. Divide between 4 plates.

Pat scallops dry and sprinkle with the remaining pepper. In a 12-inch heavy skillet heat the remaining olive oil over high heat (if you don’t have a 12-inch skillet, do the scallops in two batches). Add the scallops and cook 2 minutes. Turn and cook another 2 minutes. Transfer scallops to a plate and cover.

Add shallots to the pan and cook until shallots are golden. Add the grapes and lemon juice and bring to a simmer. Stir in any accumulated scallop juices.

Top each plate of watercress with scallops, grape sauce, and finish with the chopped hazelnuts.