- 1
**Make the mac and cheese:** Cook macaroni in salted boiling water until al dente; drain and set aside. In the same pot, melt butter over medium heat, whisk in flour and cook 1 minute. Slowly whisk in milk and cook until thickened, 3-4 minutes. Remove from heat, stir in cheddar and American cheese until melted. Season with dry mustard, salt, and pepper. Add cooked pasta, stir to combine, and keep warm on lowest heat.
- 2
**Toast the buns:** Heat a cast iron skillet or griddle over medium-high heat. Place buns cut-side down and toast until golden, about 1 minute. Remove and set aside.
- 3
**Smash the patties:** Increase heat to high. Add a thin film of oil to the skillet. Place one 6 oz beef ball in the skillet and immediately press flat with a heavy spatula or burger press to about 1/4-inch thick. Season generously with salt and pepper.
- 4
**Cook the patty:** Cook undisturbed for 2 minutes until a dark crust forms on the bottom. Flip, lay one American cheese slice on top, and cover the pan with a lid for 30 seconds to melt the cheese. Remove patty and repeat for second burger if making two.
- 5
**Build the burger:** Spread burger sauce on the bottom bun. Layer on the dill pickle chips, then set the cheese-topped patty on top.
- 6
**Add mac and cheese:** Spoon a generous 1/2 cup of hot mac and cheese directly over the patty.
- 7
**Finish and serve:** Scatter bacon crumbles over the mac and cheese, add jalapeño rounds, and cap with the top bun. Serve immediately with fries or chips.