In a large bowl, stir together the flour, salt and baking powder. With a pastry blender, a fork or your hands, gradually work in the lard or shortening until it is all incorporated. Add enough warm water to make a soft but not sticky dough. Turn out onto a lightly floured board and knead for 5 minutes.
Divide the dough into 1/4 cup (3 oz) portions and form them into balls. Roll each ball into a flat round about 6 inches in diameter and 1/8 inches thick. Heat a large heavy skillet over medium high heat. Place the tortillas one at a time into the dry hot skillet; cook until brown on one side, then turn and brown the other side. Remove from the skillet and keep warm in cloth towel.