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.
Source: Southwest cookbook