Potato Gratin with Mushrooms

Gratin is the most comforting French comfort food and is not hard nor time consuming to make. Though a gratin is technically any dish with a crunchy top, it has typically come to reflect one which is filled with cream and a carbohydrate and topped with cheese. While a gratin can be made of anything—squash, potatoes, or only mushrooms, it is the potato which provides the most calories and glucose and thus pairs better against the sheer amount of simple cream and cheese. Like most dishes, people tend to overdo gratins, filling them with more cheese, spices, and other ingredients which drown the vegetables, overpower the cream, and distract from the pure magic that happens with simple, minimalist ingredients. Most cream these days includes gums and binders to cheat you out of really thick, good cream, and these gums cause flatulence and gastrointestinal stress. Search for and demand real cream from your grocers instead of these imposter products which compromise your health and comfort. If you have issues with alcoholism and addiction or insomnia please read those chapters in my book as potato can potentially contribute to those problems and you should be aware of the nuances of consuming potato due to its solanine content. The picture above uses portobello mushrooms instead of crimini. If you chose to use portobellos follow the addendum below. Using crimini is a bit more delectable as it adds just a hint of mushroom flavor to the gratin.

POTATO GRATIN WITH MUSHROOMS

3 lbs Yukon or Gold Potatoes, peeled and thinly sliced
1 package (8 oz) brown Crimini Mushrooms, thinly sliced
2 tbsp flour (einkorn or spelt)
1 pint heavy cream (no additives!)
1/2 cup whole milk
3 tbsp butter
6-8 oz good, sharp cheese shredded (parmesan, gouda, asiago)
2 pinches nutmeg
1 tsp sea salt

Preheat oven to 300˚ F. Toss sliced mushrooms with flour to coat evenly. This will prevent the mushrooms from watering down the gratin. Mix together the milk and cream, then on the bottom of a casserole dish spread a thin layer. Now, lay down one layer of potatoes, then a layer of mushrooms, very lightly salt this layer and just very, very lightly dust with a pinch of nutmeg, then pour a little more cream over it all and repeat until reaching the top of the dish or the last of the potatoes and mushrooms, but only put the last pinch of nutmeg on the very top layer (too much salt or nutmeg can easily overwhelm the dish). Save most of the cream for the top, but first lay down the grated cheese as the last layer, adding a few thin slices of the butter across the cheese, salt everything, then pour the remaining cream over the cheese (if you put the cheese on last without the cream it will burn and turn hard and chewy). Place a sheet of parchment paper over the dish and bake in the oven for 110 minutes or until the top is spotted with golden brown. Let rest for 25 minutes before serving. If you serve too early it will not be set.

USING PORTOBELLOS

Portobellos are just the more mature form of the same small crimini types, but being larger they can potentially sweat more water into the gratin and as such must be pre-cooked to prevent this, otherwise your gratin will be watery and chewy. Remove the stems from portobellos, slice thin, then sauté in a pan until most of the water is evaporated (not all though, you want some mushroom juice to go into the gratin still). Omit the flour and add these slices to the layering of potatoes as normal.

NO MUSHROOMS

Of course, classic gratin without mushrooms is amazing on its own. Simply omit from recipe.