Begin by filling a large pot with water, adding salt, and bringing it to a boil. Add the pasta shells and cook until al dente, typically around 8-10 minutes. Drain and set aside.

In a large skillet, heat olive oil over medium heat. Add the ground beef, chopped onions, and minced garlic, cooking until the beef is browned, about 5-7 minutes.

Pour in the beef broth and sprinkle in the Italian seasoning. Stir and bring to a gentle simmer for about 5 minutes.

Lower the heat and gradually stir in the heavy cream. Simmer for another 5 minutes until the sauce thickens.

Fold the cooked pasta shells into the sauce, adjusting seasoning with salt and pepper. Cook for an additional 2-3 minutes.

Serve the creamy beef and shells on warm plates, garnished with additional Italian seasoning if desired.