Philly Mac Recipe

Prep steak

If your steak is not already thinly sliced, place it briefly in the freezer (20–30 minutes) to firm slightly, then slice across the grain into very thin strips about 1/8–1/4" thick. Lightly season with 1/2 teaspoon kosher salt and 1/2 teaspoon black pepper.

Sauté vegetables

Heat a large skillet over medium-high heat. Add 1 tablespoon olive oil and 1/2 tablespoon butter. When hot, add sliced onions, green peppers, and mushrooms. Cook, stirring occasionally, until vegetables are softened and beginning to brown, about 6–8 minutes. Add minced garlic in the last 60 seconds, then transfer vegetables to a bowl and set aside.

Cook steak

Wipe the skillet if necessary, return to high heat, add remaining 1 tablespoon olive oil. Add the thin steak slices in a single layer (work in batches if needed to avoid crowding). Sear without moving for 30–45 seconds, then stir and continue cooking until just browned and cooked through, about 1–2 minutes total per batch. Season with remaining 1/2 teaspoon kosher salt, 1/2 teaspoon black pepper and 1 teaspoon Worcestershire sauce. Return vegetables to the pan, toss with the steak briefly to combine, then remove from heat and keep warm.

Bring a large pot of salted water to a boil and cook pasta according to package directions until al dente. Reserve 1/4 cup of the pasta cooking water, then drain the pasta and return to the pot off the heat.

Make roux and milk base

In a medium saucepan over medium heat, melt 2 tablespoons butter. Whisk in 2 tablespoons flour and cook, whisking constantly, for 1–2 minutes until the raw flour smell is gone and the mixture is bubbling but not browned.

Add milk

Slowly whisk in 1 1/2 cups whole milk, a little at a time, whisking constantly to avoid lumps. Bring to a gentle simmer and cook for 2–3 minutes until the sauce thickens to a creamier consistency that coats the back of a spoon.

Finish cheese sauce

Reduce heat to low. Remove the saucepan from direct heat and stir in the cream cheese (if using) until melted. Gradually add the shredded provolone and mozzarella, stirring until smooth and fully melted. Stir in 1/2 teaspoon salt, 1/4 teaspoon black pepper and 1/2 teaspoon mustard (if using). If the sauce is very thick, whisk in up to the reserved 1/4 cup pasta water 1 tablespoon at a time to loosen to desired consistency.

Combine pasta, sauce, and steak

Add the drained pasta to the pot with the cheese sauce and toss until evenly coated. Add the steak and vegetable mixture to the pasta and gently fold to combine, heating together over very low heat for 1–2 minutes so everything is hot and well integrated. Taste and adjust seasoning with additional salt, pepper, or Worcestershire if desired.

Serve

Portion the Philly Mac into bowls or plates. Garnish with chopped parsley and red pepper flakes if using. Serve immediately so the cheese sauce is creamy and melty.