In a large pot you don’t intend to use for anything else, heat rosin over low heat until it is fully melted and simmering. (Resist the urge to increase heat so the rosin will melt faster.) Gently add potatoes and cover with a lid. Simmer until potatoes are fork tender, about 30 minutes.
While potatoes are cooking, lay several layers of newspaper across a large surface. Using a wooden spoon, pull potatoes from rosin and lay on newspaper. Let rest until cool to the touch, then peel away rosin layer like a hard boiled egg shell, discarding rosin.
Suggestions for serving potatoes: sautéed with butter and herbs, lightly crushed and tossed with butter and cheese, topped with crème fraîche and caviar.