Place 1 tsp oil in a cast iron skillet and get it hot over medium high heat.
Section out hamburger into 4 equal size portions.
Place hamburgers in hot skillet and smash with a spatula until meat is thin. Cook a couple minutes until the underside gets a bit crisp then flip. Cook one min and top each burger with cheese and allow to melt.
While the burgers are cooking, mix gravy mix with beer (1/4 c for mild beef flavor – ½ c for more beer flavor). Once the beer and gravy mix have combined well place mixture with enough water to make 1 cup (3/4 c water to ¼ c beer for example) and bring to boil while whisking over medium high heat until thickened.
To saute the mushrooms heat pan over medium high heat, add 1 tsp oil and mushrooms. Season well with salt and pepper to liking and cook until mushroom soften. Once the mushrooms lose their moisture, deglaze pan with beer and cook until most of the moisture is gone.
Once the burgers are cooked and the cheese is melted, remove the burgers and set aside.
Place hamburger buns in the hot skillet to toast the buns for around a minute.
To assemble, stack the cheese burgers on the bun and top with beer gravy and sauteed mushrooms.
Chef Mike Castaneda is ranked one of the Top 10 cooks in America by Food Network and placed Top 10 in the World Food Championships. Mike also served 5 years in the Army as a Short Range Air Defenseman.