How to Make It
In a large bowl, whisk the flour with the baking powder and salt. Add the bacon fat and mix with your hands to evenly moisten the flour. Add the water and scallions and stir just until the dough comes together. Scrape the dough out onto a floured work surface and knead just until smooth. Roll the dough into 20 even balls and transfer to a baking sheet. Cover with plastic wrap and let stand for 20 minutes.
Heat a cast-iron griddle or large skillet over moderately high heat. Work with one piece of dough at a time: On a lightly floured work surface, dust a ball of dough with flour and roll it out to a 9-inch round, about 1/8 inch thick. Griddle the tortilla, turning once, until browned in spots and pliable, about 30 seconds per side. Wrap the tortilla in a towel and repeat with the remaining balls of dough.