01 -
Spread parchment paper on baking sheets and set frozen roll dough apart so they don't touch. Cover them loosely with plastic wrap and let them sit at room temperature until they're about double their size, which will take 3 to 5 hours.
02 -
In a big skillet, cook the ground beef over medium heat. Halfway through cooking, toss in the butter, onion, and cabbage. Cook until the beef is brown and the veggies are soft. Give the mixture a few minutes to cool.
03 -
On a floured surface, roll each dough ball into a round shape. Spoon some filling in the center of the dough, then pull up the edges and pinch the seams to seal them. Gently roll over the seams to make sure it's closed. Place the seam side down on parchment paper and let them rise for another 30 minutes.
04 -
Heat the oven to 350°F. Mix the egg and milk together, then brush it onto the runzas. Bake them for about 18 to 20 minutes, turning the tray halfway through, until they're golden on the outside.