Sprinkle beans with salt, and arrange in steamer basket over boiling water. Cover and let steam 8-10 minutes or until crisp-tender. Plunge green beans into cold water to stop the cooking process and drain. Melt butter in a dutch oven over medium-high heat, add green onions and saute until tender. Add green beans, rosemary, nuts and lemon juice. Cook, stirring constantly until thoroughly heated. Sprinkle with lemon rind and serve immediately.