1. Use a sharp knife to trim artichoke stems. Cut off 1 inch from top of artichokes. Use kitchen shears to trim sharp points from each leaf. Remove bottom few leaves from base of artichoke.
2. Place artichokes in a medium saucepan and add about 1 inch
of water. Bring to a boil then reduce to a simmer. Cover and cook 40 minutes or until a leaf can easily be pulled off.
3. Meanwhile, in a small bowl, combine yogurt, lemon juice, zest and garlic powder. Halve artichokes and serve with dip.