01 -
Heat a cast iron pan and cook the ground beef. Let parts of the meat develop a dark crust—about half—before breaking it up.
02 -
Take the browned beef out of the pan and set it aside. Leave the juices behind in the skillet.
03 -
Melt the butter in the pan and toss in the diced mushrooms, peppers, and onions. Let them sit for a minute or two to brown, then stir and repeat until fully colored.
04 -
Add the cooked beef back into the pan.
05 -
In a small cup, combine the cornstarch with beef broth and mix until smooth.
06 -
Pour the broth mixture into the skillet along with ketchup, Worcestershire sauce, black pepper, and salt. Stir until everything is combined well.
07 -
Simmer the mixture for 3-5 minutes. It should be a little saucy with just enough liquid for about 25% of the ingredients to sit under it.
08 -
Turn off the stove and mix in the chopped cheese until melted.
09 -
Spoon the beef mix onto brioche buns that are lightly toasted.