Melt butter in a cast iron skillet over medium high heat. Divide ground beef into 4 equal parts and gently form into balls. Season on all sides with Kosher salt.

Once the butter starts to sizzle, add balls of ground beef to the pan. You may need to cook them in batches depending on the size of your pan. 

Smash burgers into the pan using the flat end of a spatula with a wooden spoon handle pressing down heavily on top of it. Your goal is to smash the burger until it's slightly larger than the size of your bun.

Cook for 2-3 minutes or until a dark golden brown crust forms.

Flip burgers, divide cheese and chiles evenly between burgers, and cook for another 2 minutes. 

Assemble burgers by placing the burger on top of the inside of the bottom bun. Then add the top bun and enjoy!