1. Adjust oven rack to low position and preheat oven to 400 degrees F. Line a baking sheet with foil and spray with vegetable cooking spray.
2. Peel and finely chop 1 onion and set aside. Halve remaining 3 onions crosswise (do not peel), make two X marks near the tip of each onion half, and place cut side down on baking sheet. Roast until tender when pierced with a thin skewer or knife tip and dark brown on bottom, about 30 minutes. Cool for 10 minutes. Remove and discard skin and roughly chop onions.
3. In a small saucepan, heat broth to a simmer over medium heat, about 5 minutes. Reduce heat to very low and continue to simmer. Meanwhile, in a large pot heat oil over medium heat until hot, about 1 minute. Add reserved chopped raw onion and cook, stirring frequently, until onion is translucent, about 3 minutes. Add garlic and cook, stirring frequently, 1 minute. Add rice, stir to coat with onion mixture, and cook until edges of grains begin to turn translucent, about 2 minutes.
4. Add wine, reduce heat to medium-low, and cook, stirring frequently, until wine is absorbed, about 2 minutes. Add 1 cup warm broth and cook, stirring occasionally, until it has been absorbed, about 5 minutes. Add remaining broth 1 cup at a time and cook until it has been absorbed between each addition and rice appears moist, creamy, and cooked through, but still a little chewy, about 15 minutes total.
5. Add salt, pepper, and chopped roasted onions and continue to cook, stirring occasionally, until onions are heated through and rice is tender and appears somewhat drier but still saucy and creamy, about 4 minutes. Add cheese and arugula and cook, stirring occasionally, until arugula is wilted, about 1 minute. Serve immediately.
Source: Hannaford fresh Magazine, May - June 2009