You can buy PHO rice noodles dried or fresh in any Vietnamese market, Whole Foods or specialty grocer. If you have a choice, always go with the fresh variety, which is chewier and more plump than dried. If you are using fresh noodles, you’ll be blanching them, which simply means you’re going to plunge them into boiling water for a few seconds to soften them before giving them a rinse under cold water. Most dried rice noodles (sometimes called cello noodles), require soaking in hot or boiling water. Be sure to check the directions.