Clean the beet greens, removing the leaves and setting them aside for another use. Trim the stalks on the cut into 6 inche long pieces.
Bring 1 quart of water to a boil and set up an ice bath nearby. Cook the stalks for 2 to 3 minutes in the boiling water until tender, then shock in ice water. Once cooled, remove the stalks and pat dry. Cut the stalks into 1/4-inch julienne and set aside.
In a 12 to 14-inch saute pan, heat the 2 tablespoons olive oil over high heat until almost smoking. Add the beet stalks, prosciutto, orange zest, cinnamon, remaining 1 tablespoon of olive oil and red onion and toss to coat, about 30 seconds. Splash with the orange juice and toss again. Season with salt and pepper and divide among 4 plates. Serve immediately, with fish or grilled meats.