01 -
On baking sheets lined with parchment, arrange your frozen rolls leaving space between them. Cover loosely with plastic and let them sit out at room temp until they grow to twice their size, which takes around 3 to 5 hours.
02 -
In a big skillet over medium heat, start browning the beef. Partway through, throw in the butter, cabbage, and onion. Keep cooking until the meat is fully browned and the veggies are tender. Let it cool a bit.
03 -
Spread flour on your surface, then flatten each roll into a round shape. Scoop some filling into the center, fold up the edges, and pinch them shut. Give them a gentle roll to seal. Put them seam-side down on parchment paper and allow to rise another 30 minutes.
04 -
Set the oven to 350°F. Mix the egg and milk together, then brush over the runzas. Bake them for 18 to 20 minutes, turning the tray halfway through, until they're a nice golden color.