Bring a large pot of salted water to a boil. Cook 12 oz penne according to package directions until al dente (usually 9–11 minutes). Reserve 1 cup pasta water, then drain and set aside.

Heat 1 tbsp olive oil in a large skillet over medium heat. Add chopped onion and bell pepper. Cook, stirring occasionally, until onions are translucent and peppers soften (about 6–8 minutes). Season lightly with salt.

Push the onions and peppers to the side. Add sliced mushrooms and a pinch of salt. Cook until the mushrooms release their moisture and start to brown, about 5 minutes.

Add the 1 lb ground beef to the pan. Break it up and cook until no pink remains and juices run clear—about 6–8 minutes. Season with salt and pepper. Optional: drain excess fat for a leaner pan sauce.

Reduce heat to low. Pour in 2 cups heavy cream and bring to a gentle simmer—do not boil hard or the cream can separate. Gradually stir in 8 oz shredded provolone until melted and smooth. If the sauce seems too thick, add reserved pasta water a little at a time until desired consistency. Taste and adjust salt and pepper.

Add drained penne directly into the skillet (or transfer sauce to the pasta pot). Toss gently to coat every piece. Warm together for 1–2 minutes so flavors marry.

Stir in chopped fresh parsley or oregano and a crack of black pepper. Let the pasta rest 2 minutes; the sauce will thicken slightly.

Plate hot. Optionally top with extra shredded provolone and broil for 1–2 minutes for a bubbly crust. Enjoy immediately.