Preheat the oven to 400 degrees Fahrenheit. Add the cream cheese, grated mozzarella, mayonnaise, Italian seasoning, salt and pepper to a mixing bowl. Crush the garlic and add to the bowl. Mix well to combine.
Spoon the cheese mixture into the base of a medium sized oven dish, creating a thick and even layer. Spoon the tomato sauce/passata over the cheese layer. Smooth the sauce gently over the cheese so that it is completely covered.
Sprinkle the grated cheddar cheese and parmesan shavings over the top of the tomato sauce layer. Arrange evenly distributed slices of salami over the top of the cheese. Transfer to the oven to bake for 18 minutes or until hot through, the cheese is melted and the dip is bubbling and golden. Serve hot with your favorite low carb dippers.