Trim and wash 1 1/2 pounds green beans. Trim, seed, and thinly slice 2 yellow or red sweet peppers. Blanch green beans in a large pot of boiling, salted water for 4 to 5 minutes. Drain; rinse in cold water. Drain again. (This can be done up to 24 hours ahead. Transfer to a sealed storage bag; chill.) In a large skillet, heat 3 tablespoons olive oil or butter. Cook peppers briefly, about 2 minutes. Add beans. Cook and stir 3 to 5 minutes more or until vegetables are crisp-tender. Toss with 1/3 cup chopped toasted hazelnuts or almonds; season with salt and ground black pepper. Makes 8 servings.