How to Make It
In a large pot of boiling salted water, blanch the beans until bright green, about 3 minutes; drain and pat dry. In a very large, deep skillet, cook the shallots in the olive oil over moderate heat until they are softened, about 5 minutes. Add the beans and cook, tossing, until heated through. Add the lemon juice and walnuts, season with salt and pepper and serve.