Shake Shack copycat burger with homemade potato buns and shack sauce

Microwave the potato, take the skin off and mash it with nothing added.

Put flour, instant yeast, brown sugar, salt, egg, mashed potato, melted butter, milk and lukewarm water in the mixer with the dough hook.

Mix on low for five minutes, then medium.

Work in a little more flour until the dough is tacky rather than sticky.

Grease a bowl, add the dough, cover tightly with plastic wrap.

Rise one hour minimum, until doubled.

Deflate, divide into eight, roll each into a ball.

Space the balls on a parchment lined baking tray.

Rise another hour.

Brush half the buns with beaten egg, leave the rest plain.

Bake at 350F for 25 to 30 minutes.

Stir ketchup, mayo, Dijon, dill pickle brine and cayenne together for the shack sauce.

Rub butter on the buns while hot, then cool to room temperature.

Slice tomatoes a quarter inch thick; ready lettuce and American cheese.

Form one pound of beef into four patties pressed into one inch pucks; he combines them into three to match the bun width.

Season the pucks with salt and pepper on both sides.

Butter both cut sides of the bun.

Toast the bun cut side down in a heavy pan on medium low for two to three minutes until golden brown inside.

Raise to medium and heat the pan two to three minutes.

Place the pucks in the pan with space between and smash each to a third of an inch with a sturdy metal spatula.

Cook two and a half minutes, flip, add the cheese and cook another minute.

Spread a tablespoon of sauce on the top bun, add lettuce and two slices of tomato, then the patty.