1. Mix together the dry ingredients.
2. Stir in the corn oil, then the lukewarm water. Use enough water to make a soft dough that you can press into a very thin sheet between your fingers. If the dough is too sticky to work, add more flour.
3. Divide the dough into 6 balls.
4. Roll the balls into flat, round disks about 1/8 inch thick between 2 sheets of wax paper with a rolling pin, or flatten into disks with a tortilla press.
5. Cook each disk on both sides on a very hot unoiled griddle until flecked with brown, less than 1 minute altogether. Don’t overcook or the tortillas will get hard. You may brush cooked tortillas with corn oil, or spoon them with chili sauce and roll them up, using the Mexican fillings. Sauces such as guacamole or hot sauce are also suitable. Some cooks will fry the filled tortillas in 1/4 inch of oil, but this creates food unnecessarily high in fat.
A healthier alternative is brushing the outside of the rolled tortilla with corn oil and baking it 10-15 minutes in a 350° F oven.
Note: You may keep cooked tortillas warm in a covered baking dish in an oven on the lowest setting, or refrigerate or freeze them, then reheat briefly on a hot griddle.