When preparing to test potential holiday recipes, I have a very short checklist that I go through when sorting recipes:
Does it have cheese? Does it have bacon? Does it have potatoes? Does it have cheese? (Cheese is very important, obviously.)
If the answer to any of the above is “yes” then it’s a no-brainer – it goes into the “definite” stack, meaning I have to try the recipe. If the answer is “yes” to all three, then it’s a stop-the-presses situation, in which I immediately run to the store and have the oven preheating within 30 minutes. As you can tell, this recipe was the holy grail of checklist worthiness. I’m always trying to find something different to do with potatoes for holiday side dishes, to spice things up a little bit. Everyone expects (demands?) mashed potatoes, the family always goes nuts for scalloped potatoes, and then there’s the requisite sweet potato dish, but I like to mix things up a bit. I suspect that I’m going to be mixing up a massive dish of this gratin – it’s the jackpot of side dishes!
This gratin is prepared in a somewhat similar fashion to traditional scalloped potatoes, with the main difference being the cream sauce is not as rich here and less of it is used, so it is primarily soaked up by the potatoes, leaving you with a layered potato casserole. Not only are there potatoes; there are also two distinct layers of a bacon/mushroom mixture and loads of Gruyère cheese. The dish is baked until everything on top is golden brown and bubbling, which we all know means crusty, cheesy, melt-in-your-mouth deliciousness.
I’ll be continuing my quest for new Thanksgiving recipes over the next couple of weeks, but this recipe has definitely secured itself a spot on the Thanksgiving menu!
Fry the bacon in a 12-inch cast iron skillet over medium heat until browned and crisp. Remove with a slotted spoon to a paper towel-lined plate to drain. Pour off all but 2 tablespoons of the bacon grease.
Return the pan to the stove over medium heat and add the onion, cooking until they begin to soften, about 3 minutes. Add the mushrooms and continue to cook until all of the liquid has evaporated and the mushrooms are cooked down, another 5 minutes or so. Add the garlic, thyme, salt and pepper, and cook, stirring frequently, until the garlic is fragrant, another 1 to 2 minutes. Remove from the heat and stir in the cooked bacon; set aside.
In a small saucepan, bring the cream, milk and nutmeg to a simmer over medium-low heat. Remove from heat.
Pour a small amount of the cream mixture into the bottom of a 2-quart baking dish, using just enough to cover the bottom. Layer half of the potatoes over the bottom of the dish, overlapping them as you lay them down. Top the potatoes with half of the bacon and mushroom mixture, then half of the Gruyère. Layer on the remaining potatoes, overlapping them again as needed. Pour the cream mixture evenly over top of the potatoes, ensuring that all of the potatoes are moistened. Top with the rest of the bacon mixture, and then the remaining Gruyère.
Cover the pan with foil and bake until the potatoes are easily pierced with a sharp knife, about 45 to 55 minutes. Remove the foil and return the dish to the oven for an additional 20 minutes, or until the top is golden brown. Let the gratin sit for at least 15 minutes before serving.