In a medium saucepan cook beans, covered, in a small amount of boiling salted water for 5 to 10 minutes or until crisp-tender; drain.
Meanwhile, in a small saucepan melt butter over medium heat. Add walnuts and ginger; cook for 2 to 3 minutes or until nuts are toasted. Remove from heat; stir in lemon peel and lemon juice. Stir nut mixture into cooked beans.