Special equipment: a tortilla press and a gallon-size resealable plastic bag
Combine the masa harina, lime juice, sriracha, vegetable oil, salt and 2/3 cup water in a small bowl. Mix well with a spoon. As soon as a dough starts to come together, knead with your hands until a soft dough has formed and the ingredients are fully combined. Divide into 8 balls and cover with a damp cloth to keep moist.
Cut a gallon-size resealable plastic bag along both seams and lay it open on a tortilla press. Place a dough ball in the center of the lined press and gently press with even pressure¿the tortilla should measure 5 inches.
Heat a nonstick pan over medium-high heat. Carefully peel the tortilla off the plastic bag and place it in the pan. Cook for 50 seconds on each side. Transfer the cooked tortilla to a plate and cover with a cloth to keep warm. Repeat with the remaining dough. Serve immediately.
Unused tortillas may be stored in a sealed plastic bag in the refrigerator for up to a week. Microwave them for 20 seconds to reheat.