In a medium-sized bowl, whisk together the flour, baking powder, and salt.
Add the lard (or butter, or shortening; if you're using vegetable oil, add it in step 3). Use your fingers or a pastry blender to work the fat into the flour until it disappears. Coating most of the flour with fat inhibits gluten formation, making the tortillas easier to roll out.
Pour in the lesser amount of hot water (plus the oil, if you're using it), and stir briskly with a fork or whisk to bring the dough together into a shaggy mass. Stir in additional water as needed to bring the dough together.
Turn the dough out onto a lightly floured counter and knead briefly, just until the dough forms a ball. If the dough is very sticky, gradually add a bit more flour.
Divide the dough into 8 pieces. Round the pieces into balls, flatten slightly, and allow them to rest, covered, for about 30 minutes (see tips, below). If you wish, coat each ball lightly in oil before covering; this ensures the dough doesn't dry out.
While the dough rests, preheat an ungreased cast iron griddle or skillet over medium high heat, about 400°F.
Working with one piece of dough at a time, roll into a round about 8" in diameter. Keep the remaining dough covered while you work. Fry the tortilla in the ungreased pan for about 30 seconds on each side. Wrap the tortilla in a clean cloth when it comes off the griddle, to keep it pliable. Repeat with the remaining dough balls.
If there are leftovers, allow them to cool completely, then wrap tightly in plastic and store in the refrigerator. Reheat in an ungreased skillet, or for a few seconds in the microwave.