Preheat the oven to 350 degrees.
In a large skillet over medium high heat on the stove, cook the ground beef, sausage and onions until the meat is completely browned. Drain any extra fat.
While the meat is browning, blanch the broccoli in boiling water for 5 minutes and then rinse and drain well with cold water.
Add the Italian seasoning, salt and pepper to taste and the minced garlic to the skillet, and stir to combine.
Reduce heat to medium low. Place the cream cheese in the skillet, and stir until well incorporated and completely melted.
Add the parmesan cheese and heavy whipping cream to the skillet, and continue to cook for another few minutes.
Pour ⅔ of the meat mixture into the bottom of a 9x13 baking dish.
Top the meat mixture with the broccoli and then the remaining ⅓ of the meat mixture.
Sprinkle the mozzarella cheese on top of the casserole, and bake for 25-30 minutes until browned and bubbly. Top with chopped parsley for garnish.