Slice the onion and bell pepper into bite-sized pieces. Slice the mushrooms if using.

Heat the olive oil in a large deep skillet over medium-high heat.

Add the ground beef, diced peppers, onions, mushrooms, and garlic to the skillet all at once.

Cook for 8–10 minutes, breaking up the beef as it cooks, until the meat is browned and the vegetables are tender. Drain excess grease if needed.

Stir in the salt, pepper, Italian seasoning and Worcestershire sauce. Cook another minute until fragrant.

Whisk together the beef broth and cornstarch. Pour into the skillet and stir. Add the uncooked penne and stir to combine.

Bring everything to a boil, then reduce to a simmer.

Cook uncovered for 10-12 minutes, stirring occasionally, until the pasta is tender. Make sure the pasta stays submerged in the broth as it cooks.

Reduce heat to low.

Stir in the sour cream along with half of the mozzarella and provolone cheese. Continue stirring until smooth and creamy.

Sprinkle the remaining cheese evenly over the top. Place a lid on the skillet for about 2–3 minutes until the cheese is completely melted. Garnish with fresh parsley if desired and dig in!