Cut the onion into dices and pan-fry in extra virgin olive oil. Add the rice, make it toast, then simmer with the wine and stir until wine is absorbed. Then, start adding some vegetable stock. Cook over moderate heat stirring often.
Meanwhile, sauté the carrots in a pan for a few minutes and cut them into dices.
Halfway through the cooking, add saffron and carrots and let it cook stirring often.
When the rice is ready, cream the risotto with cold butter and grated Parmigiano.