In a large skillet with a tight fitting lid, brown the ground beef with the chopped onion, chopped green bell peppers and minced garlic. Drain, if needed.
Pour in the chicken stock and then add the pasta shells. Press the shells into the liquid, so that they are all "underwater." If needed, add a couple more TBSP of broth. Put the lid on and cook over medium heat for 8 to 10 minutes, or until pasta has cooked through.
Once pasta is cooked, stir in the softened cream cheese and shredded mozzarella cheese.
Serve Philly Cheesesteak Goulash with chopped parsley garnish, and favorite side dishes.