roated onion soup recipe -- question!!!

Okay, I have a bag of onions and need to use some up. I found this recipe, which looks simple enough, but my question is about the Brandy -- I am not keeping alcohol in the house right now -- so do I just leave it out or should I substitute something?

Thanks
Roasted Onion Soup Recipe:
4 servings, about 1 1/4 cups each
Active Time: 20 minutes
Total Time: 1 hour 10 minutes
Ingredients
• 3 Spanish onions, cut in half lengthwise and thinly sliced
• 3 large shallots, cut in half lengthwise and thinly sliced
• 1 large head garlic, cloves separated, peeled and cut in half
• 2 teaspoons extra-virgin olive oil
• 4 cups reduced-sodium chicken broth, divided
• 1/4 cup brandy
• 1 tablespoon chopped fresh thyme
• Salt, to taste
• Freshly ground pepper, to taste
• 1/4 cup freshly grated Parmesan cheese, preferably Reggiano
Preparation
1. Set oven rack at the lowest level; preheat to 450°F.
2. Combine onions, shallots, garlic and oil in a large shallow roasting pan. Roast, stirring every 5 minutes, until the onions are golden, 20 to 25 minutes. Remove from the oven and pour in 1 cup of the broth; stir, scraping the bottom of the pan to loosen and dissolve any caramelized bits. (The liquid will become quite dark.)
3. Transfer the onion mixture to a soup pot and add brandy, thyme and the remaining 3 cups broth. Bring to a boil; reduce heat to low and simmer, covered, for 30 minutes. Season with salt and pepper. Divide between 4 bowls and sprinkle with Parmesan.
Nutrition
Per serving: 183 calories; 4 g fat ( 2 g sat , 2 g mono ); 9 mg cholesterol; 21 g carbohydrates; 8 g protein; 2 g fiber; 516 mg sodium; 309 mg potassium.
1 1/2 Carbohydrate Serving
Exchanges: 3 vegetable, 1/2 fat