Cheesy Scallop Potatoes

* Preheat oven to 375F
* Arrange the potatoes and onions in a prepared baking dish, staggering potato and then topping with sliced onions.
* In a saucepan, melt butter over medium heat. Mix in the flour and then slowly mix in half and half + heavy cream. Add in dried seasonings and mix until combined for about 2 minutes.
* Turn off heat. This process goes super fast! Slowly add in grated cheddar and Gouda cheese while stirring until there are no lumps. Sauce should thicken into a cheese sauce consistency but not too thick. You want to be able to pour the cheese sauce on top of the potatoes and it drip inbetween the crevices of the potatoes.
* Pour the cheese sauce over the potatoes ensuring cheese sauce is inbetween sliced potatoes and on bottom of pan. You can rearrange potatoes so that cheese sauce can incorporate into every crevice of each scalloped potatoes, if needed.
* Add more grated cheese on top
* Cover the dish with foil and bake for 45 minutes or until potatoes are fork tender.
* Remove foil from top and bake an additional 20-25 mins or until cheese on top browns. Add dried parsley for garnish.