Cut trimmed green beans into 2-inch pieces.
Arrange beans in a steamer basket over boiling water. Cover and steam 5 minutes. Plunge beans into ice water to stop cooking process; drain.
Sauté 1 cup chopped ham in a large skillet over medium-high heat 2 minutes; add green beans, and sauté 3 minutes. Add crumbled blue cheese, and cook, stirring constantly, 2 minutes or until cheese is melted. Add 1/3 cup chopped walnuts and 1 teaspoon pepper, tossing well. Serve immediately.