I learned this trick from my neighbor Pamela. Save your veggie scraps – peels, celery tops, kale and broccoli stems, ends of carrots, onion and leek greens, etc. Keep them in a bag in the freezer until you accumulate enough to make stock.
Put them in a pot with enough water to cover them, and cook for an hour or two. Then strain the veggies out (I squeeze them to get the juice out) and you have stock that can be used right away or frozen for later.