You can make tortillas Nicoyan style at home. All you need is lime-treated corn flour, which is called masa harina.
Technique tip: Cool any unused tortilla to room temperature and store tightly wrapped in a kitchen towel in the refrigerator for up to 1 day. Reheat on a baking sheet 4 to 6 inches from a heated broiler for 10 seconds.
Swap option: If you want to make it even easier, you can purchase corn tortillas at almost any grocery store; just make sure the list of ingredients is short and simple, about like this recipe.
Special equipment: To make this recipe easier, you may want a tortilla press. You can also make tortillas by hand, but it takes practice to roll the dough thin enough.
Whisk the masa harina and baking soda in a large bowl. Add 1½ cups warm tap water and stir until a soft dough forms (if the mixture won't form a soft ball of dough, add warm water in 1 tablespoon increments until it will). Cover with plastic wrap and set aside for 5 minutes.2.
Turn the dough out onto a clean, dry work surface. Knead gently for 1 minute. Divide it into 16 equal pieces, each about the size of a small plum.3.
To use a tortilla press, line the press with two small sheets of wax paper. Put one piece of dough between the sheets, close the press, and gently press down. Remove the dough between the wax paper sheets, then repeat with more wax paper and the remaining dough balls. To make tortillas by hand, put each dough ball between two pieces of wax paper and roll into a thin 6-inch round.4.
Set a griddle or skillet, preferably cast iron, over high heat until smoking. Remove one flattened dough ball from the wax paper and set on the griddle or in the pan. Cook for 30 seconds, flip with kitchen tongs, and cook until lightly toasted with tiny bubbles form in the tortilla, about 30 more seconds. Transfer to a clean kitchen towel, wrap gently, and continue cooking more tortillas, keeping them warm as a stack in the towel. Serve warm.