Heat the milk in a small saucepan over medium heat until tiny bubbles start to form around the edges of the pan (the milk should be 180 degrees F), 4 to 5 minutes. Immediately remove from the heat and stir in the lard until melted. Let cool for 15 minutes.
Meanwhile, whisk the flour, baking powder and salt in a large bowl until completely combined. Pour in the warm milk mixture and stir with a rubber spatula until a shaggy dough forms.
When cool enough to handle, knead the dough in the bowl until almost completely smooth, about 3 minutes; do not overwork, the dough should be soft and only slightly elastic and not sticky. Wrap in plastic and let rest at room temperature for 1 hour to relax dough.
Divide the dough into 16 balls about a scant 3 tablespoons each (or 46g.). Arrange the balls on a rimmed baking sheet and cover with a damp kitchen towel until ready to use.
Working with one dough ball at a time, roll out on a lightly floured surface to a 7-inch round.
Heat a medium cast-iron skillet or large griddle over medium-high heat.
Working with one at a time (unless using a large griddle), cook the tortillas, reducing the heat if they are getting dark too quickly, until air bubbles form on the surface and the bottom is brown in spots, about 30 seconds. Poke any large bubbles with a fork to release steam, flip the tortillas and cook until brown in spots on the other side, about 30 seconds. Stack and wrap the tortillas in a clean kitchen towel and keep warm. Repeat rolling and cooking the remaining dough balls.