How to Make It
Stir together masa harina and salt in a large bowl. Stir in 1 1/4 cups of the hot water. Knead dough in bowl until well combined and a smooth but not sticky ball is formed, about 15 times. (If the dough cracks when squeezed, it is too dry. Add remaining 1/4 cup water, 1 tablespoon at a time, until dough is the right consistency.) Cover dough loosely with plastic wrap. Let stand at room temperature at least 30 minutes or up to 2 hours.
Heat a large cast-iron skillet or comal over high. Line a tortilla press with a plastic bag to prevent dough from sticking. Divide dough evenly into 12 (about 1 3/8-ounce, 1-inch) pieces. Roll pieces into balls; cover balls loosely with plastic wrap to prevent from drying out.
Working with 1 dough ball at a time, flatten dough in prepared tortilla press to create a 6-inch round. Place flattened dough round in hot skillet. Cook until tortilla turns a pale, dry yellow color, 45 seconds to 1 minute per side. Transfer tortilla to a tortilla warmer or folded towel to keep warm. Repeat process with remaining dough balls.