"This is an old recipe from the Swedish side of the family. It is hard to record because it has been passed down from people who didn't use written recipes, but I have done my best. Cut lefsa in half for serving."
Mix potatoes, shortening, and half-and-half in a bowl; cover with plastic wrap and let stand 8 hours or overnight.
Combine flour, salt, and sugar with the potato mixture. Stir dough until uniform and form into 12 small balls.
Place balls in refrigerator; remove one at a time to keep the rest cool. Roll dough out on a floured surface using a floured rolling pin, into a very thin circle slightly smaller than the diameter of your skillet. Use more flour as needed to prevent sticking.
Heat a lefsa pan or skillet over medium-high heat. Cook the dough circle until bubbles form, about 1 minute; flip and cook until done, about 30 seconds.
Repeat rolling and cooking steps with the remaining dough.