If you want to serve this dish hot, preheat oven to 350 degrees.
In a large bowl, combine cream cheese, sour cream, mayo, and 3 tablespoons of the parm-style topping. Add the salt and cayenne pepper, and then stir until smooth.
In a pan sprayed with nonstick spray, cook the shallots and garlic over medium heat until soft (1 - 2 minutes). Set aside.
To the large bowl, add spinach, artichoke hearts, water chestnuts and garlic/shallot mixture. Stir well.
If serving dip cold, top with the remaining tablespoons of parm-style topping. If you want to serve the dip hot, transfer to a casserole dish, top with the remaining parm, and then bake for 30 minutes (or until bubbly).