BROWN ground beef in a large skillet. Drain fat.
ADD water and spice packet. To Fix It Mild, omit the cayenne pepper. To Fix It Hot, stir in entire cayenne pepper packet.
COVER and simmer for 5 minutes. For thicker chili, mix masa flour with 1/3 cup water, and stir in. Add tomatillos and simmer, covered, for 10 more minutes. Stir in cilantro and lime juice.