Vegetable Stock with Kitchen Scraps Nothing beats homemade vegetable broth and this recipe is as easy as it gets! Just start with a gallon-size sealable plastic bag containing the onions, celery and carrots and pop it in the freezer. Over time, add your vegetable scraps to the bag and once it's full, place the contents in a pot, add water and some spices and simmer away. It's a great way to reduce food waste and have delicious homemade broth ready whenever you need it. For the clearest and most flavorful stock, simmer gently--and don't stir.