The secret to Hot Bread Kitchen's richly flavorful tortillas is the masa made from freshly ground blue or white corn. Fresh masa is becoming increasingly available in cities with large Mexican populations, but masa harina, a dry corn flour, works well in the recipe below. Maseca is the most commonly available brand, but Bob's Red Mill (sold at health-food stores and some supermarkets, or at bobsredmill.com) has better flavor.