Heat a medium skillet over low heat. Microwave sweet potato on high power until tender, 5 to 6 minutes. As soon as you are able, peel the hot potato, being careful not to burn yourself. Transfer hot potato to a plate and mash. Measure 1 cup and transfer it to a medium bowl; add butter and salt and continue to mash with a fork until smooth. Add flour and continue to mix to make a smooth dough. Cut dough into 6 pieces, pressing each into a small disk.

Working one disk at a time on a floured work surface, roll each piece of dough into an 8-inch round. (If you’re near the stove, you may want to start cooking the tortillas while you finish rolling the dough.)

Increase heat to medium-high. Working one at a time, cook tortilla until spotty brown, 30 seconds to a minute. Flip the tortilla and cook until spotty brown on the remaining side, about 30 seconds longer. Serve warm. (Can be stored in a zipper-lock freezer bag and refrigerated for a couple of weeks or frozen for a couple of months.)