Mix the masa harina and salt in a bowl. Add the water and olive oil and mix until a smooth dough is achieved. (If it’s too sticky add a little more masa harina, or, if it’s too dry, add a drop more water.)
Divide the dough into 24 balls. Cover and leave to rest in the fridge for 10 minutes.
Flatten the balls of dough with your hands - alternatively, use a tortilla press or roll them between two layers of cling film. Flatten to approximately 3mm thick.
To cook the tortillas, lightly oil a flat griddle pan or frying pan and place over a hot heat.
Cook the tortillas for approximately one minute on each side, or until lightly coloured.