In a mixing bowl, combine the flour, salt, and baking powder (if using). Mix well.
Add the vegetable oil (or lard) to the dry ingredients and mix until the mixture resembles coarse crumbs.
Gradually pour in the warm water, mixing until a soft dough forms. You may not need all the water, so add it slowly.
Knead the dough on a lightly floured surface for about 3-5 minutes until it is smooth and elastic.
Divide the dough into 8 equal portions and shape each into a ball. Cover with plastic wrap or a kitchen towel to prevent drying.
Preheat a skillet or griddle over medium-high heat.
Roll out one ball of dough into a thin circle, about 8 inches in diameter.
Carefully place the rolled-out tortilla onto the hot skillet. Cook for about 30-60 seconds until bubbles form on the surface, then flip and cook for another 30-60 seconds until lightly browned.
Remove the tortilla from the skillet and keep it warm in a clean kitchen towel. Repeat with the remaining dough balls.
Serve immediately or store in an airtight container.