Pour the stock into a medium saucepan and heat over medium heat until it just simmers. Turn the heat down to low.
Meanwhile, in a large sauté pan, heat the oil over medium-high heat. When the oil is hot, add in the garlic and onions and cook until they are soft and translucent, about 5 to 7 minutes.
Add the Arborio rice and stir to coat it with the olive oil. Let the rice cook in the hot oil for about 30 seconds to open the grains. Pour in the wine, stir the rice, and let it cook for another 30 seconds to cook off the alcohol. Turn the heat down to medium.
Add 2 cups of the warmed stock and stir the rice until the stock is completely absorbed. Add the remaining stock a half cup at a time, stirring after each addition until all of the stock is absorbed and the rice is soft, about 20 minutes. Stir in the marjoram, salt, vegetables, and margarine and serve.
Leftovers can be stored in an airtight container, refrigerated, for up to 3 days.