4.

Place a large metal or glass pot lid over tortilla. Using kitchen towels to grip lid and pan handle, carefully invert entire tortilla so that it's resting on top of pan lid. Slide tortilla back into skillet so that the cooked side is now facing up. Use spatula to tuck down edges and create an even disk shape. Continue to cook, shaking occasionally, until tortilla is golden brown on second side and barely cooked through, about 2 minutes longer. Slide tortilla out onto a cutting board.