I thought it was a product, but I see it's more likely a homemade product. From RecipeZaar:
http://www.recipezaar.com/schwarties-hash-browns-363499
1/9 of a 9x13 pan is ~559 calories
So, take a very small portion and enjoy your meal. See if you can cut calories elsewhere (lots of veggies, with little to no butter - salad, again with little to no dressing, some fruit for dessert). For me, it's about deciding where you want to 'spend' your calories (oops - points).