Chef John's Hamburger Hash

Cut a 1/4-inch slice off the bottom each potato so it sits flat on a cutting board. Cut some more 1/4-inch slices straight down and then cut potatoes into sticks. Turn sticks and cut across to create a uniform dice. Transfer to a bowl of cold water.

Combine butter and olive oil in a skillet over high heat until butter melts. Add ground beef and cook, breaking up with a flat-edge utensil, until crumbly, about 5 minutes.

Drain potatoes and add to the beef with a nice pinch of salt. Reduce heat to medium-high and cook, stirring occasionally, until potatoes just start to soften, 5 to 7 minutes. Smooth mixture in the skillet and press against the bottom of the pan to help everything get nice and crusty.

Stir in onions and mushrooms and add another pinch of salt. Cook, stirring occasionally, until onions and mushrooms have softened up and taken on some beautiful color, 5 to 7 minutes. Season with black pepper, cayenne, and rosemary.

Add bell pepper, poblano pepper, and another pinch of salt. Cook until peppers are tender and the rest of the ingredients are dark and crispy, about 5 more minutes.

Stir in green onions and cook for a few more minutes. Remove from the heat and serve.