Think of a Hot Pocket that doesn't suck and you've got runzas.
STEP 1: MAKE THE POTATO DOUGH
From Tastebook's recipe for beer rocks.
2 large peeled potatoes cooked in water (save the water)
1 pkg yeast
2/3 cup of sugar
1 1/2 tsp. salt
2 eggs well beaten
2/3 cup butter
7 - 7 1/2 cups flour
Egg yolks and water for brushing rolls
Mash potatoes to make 1 full cup. Measure potato water to make 1 1/2 cup. Pour potato water into large bowl, add 1 pkg yeast, stir until dissolved. To the water/yeast mix, add 2/3 cup sugar, 1 1/2 tsp. salt, 2 eggs well beaten. Add 2/3 cup butter and mashed potatoes to the flour. Mix the wet and dry ingredients. Add more flour to make it easy to handle. Then knead until dough is elastic.
STEP 2: MAKE THE FILLING
I just made this filling up. It uses leftover pot roast, flank steak, whatever you got, plus roasted mushrooms.
2 lbs leftover cooked beef, chopped
8 oz leftover roasted mushrooms
(I liked using the ones I stored in the freezer because those can be a little rubbery when you thaw them out, and this recipe takes care of that)
2 tablespoons salted butter
1 tbsp Whassamatterhorn
2 large Vidalia onions, diced
2 cloves chopped garlic
1 tablespoon canola oil, plus more for the baking sheets
8 ounces greens (spinach, kale, collards, whatever)
Put the beef and mushrooms in the food processor bowl. Heat a large skillet over medium-high heat. Add the onion and garlic. Season with Whassamatterhorn until lightly browned, about 5 minutes. Use a slotted spoon to transfer it to the food processor. Without cleaning the skillet, add 1 tablespoon canola oil. Sauté the greens over high heat until wilted and the excess liquid has evaporated, about 1 minute. Add it to the food processor bowl. Pulse till it's chopped. Taste for seasoning. Add more Whassamatterhorn or Das Bigfoot.
STEP 3: ALL TOGETHER NOW
Roll out the dough. Flatten a dough ball on a heavily floured surface and roll out into a 3-by-5-inch rectangle. Then make wrapping flaps from the four corners of the rectangle by rolling out each corner thinly so you have a thick rectangle with four thinner triangular wings at the corners.
Spoon 1/2 cup of the filling into the center of the dough rectangle and wrap the flaps over it, pinching to close. Flip the bundle over in your hands, gently forming the runza into a fat football shape. Set the runza seam-side down on an oiled baking sheet. Repeat with the remaining filling and dough balls. Let the runzas rise about an inch, uncovered, about 45 minutes. Meanwhile, preheat the oven to 375 degrees F.
Whisk the remaining egg and 2 tablespoons water to make an egg wash and brush it thinly over the tops of the runzas. Dust with salt or caraway if you'd like. Bake until golden brown, 25 minutes.
Freeze baked after they firm up on baking sheet in the freezer, then store them in ziplock. Thaw for 1 hour before baking.