Preheat oven to 375 degrees. Place hazelnuts on a baking sheet and toast for 10 minutes. Cool enough to handle, then rub them in a clean kitchen towel to remove most of the skins. Chop nuts roughly, leaving some whole, set aside.
While the hazelnuts are roasting, prepare the green beans by trimming off the ends with kitchen shears or a sharp knife. Snap peas require no prep, if using snow peas trim and remove stringy spines.
Bring a pot of unsalted water to a boil, large enough to accommodate each type of bean separately. Before adding the beans prepare a large bowl of ice cold water and set nearby. Have a large slotted spoon on hand.
Blanch the beans and peas separately. Start with the peas for 1 minute, remove promptly with the slotted spoon, add immediately to the ice bath, when completely cold, drain and set aside to dry. Repeat the process with the beans but blanch for 4 minutes, shock in the ice water, drain and dry, add them to the green beans.
Using a citrus zester remove the zest from the orange in strips, avoiding the pith.
Assemble the dish by mixing all ingredients together in a large bowl, toss gently. Adjust seasoning and serve at room temperature.