Cook green beans in a large pot of boiling salted water for 4 minutes.
Prepare an ice water bath for your beans. Using a slotted spoon, remove beans and place in your ice water bath to stop cooking. Transfer to a cutting board to dry.
Add orzo to the same boiling water. Cook until tender as per instructions on package and using a colander rinse in cold water to stop cooking. Toss in a large salad bowl with 1 tablespoon of olive oil.
In a blender or mini food processor combine dill, 3 tablespoons oil, vinegar, zest and lemon juice, salt and pepper in a mini processor or blender and process until smooth.
Cut beans in 2 cm pieces and add to a large bowl or container. To the large bowl of orzo add cucumber, beans and mix in dressing. Salad can be served cold or at room temperature.