Homemade vegetable broth is a great way to use up your kitchen scraps because you don't have to just use the good part of the veggies. Carrot peels, celery leaves, the stems of herbs and the ends of onions have plenty of flavor in them. Parsnips and leeks also add a special depth of flavor to homemade broth. Freeze these scraps in a large freezer bag over the course of a couple of weeks and break it out when you have 2-3 cups worth of quality scraps. Vegetable broth can be made with almost any assortment of vegetables, but it's best to avoid those in the cruciferous family (cabbage, broccoli, Brussels sprouts, etc.) because they get bitter if they cook for too long.
1. Heat the olive oil in a large Dutch oven or stockpot over medium heat. Add the garlic, onions, celery, and carrots. Cook until softened, about 5 minutes, stirring often. Add the water, frozen vegetable scraps, bay leaves, parsley, and thyme. Reduce heat to low and simmer, partially covered, for 45 minutes. Pour the broth through a fine mesh strainer into a large heat-proof bowl or pot; discard solids. Once the broth has cooled, transfer it to airtight plastic containers or freezer bags and store it in the freezer. (Tip: Freeze it in 2-cup portions so you don't have to thaw all the broth every time you use it.)