Heat the oil in a large skillet over medium-high heat and fry the tortillas until crisp, 3 to 4 minutes; drain and transfer to a paper towel-lined plate.
Wipe the skillet clean and warm the enchilada sauce and ¼ cup water over medium heat.
Add the crisped tortillas to the skillet and cook until most of the sauce is absorbed, 5 to 6 minutes. Top with the Feta, onion, and cilantro.
