This is really more of a technique than a recipe, and there are lots of ways to vary it to suit your own tastes. For this version I started by rinsing and draining three, 15-ounce cans of Great Northern beans. I like the soft texture of the canned beans and it makes it possible to enjoy this on weeknights, but obviously you can also cook dried beans if you want a firmer end texture.
I cleaned and sliced a large leek and cooked it on medium-high heat in a couple of teaspoons of olive oil until soft, then stirred in the drained beans, some garlic paste (about a teaspoon) and a little crushed, dried thyme.
Layer this on the bottom of your baking dish–I used a 5-quart Le Creuset. For your next layer, you want to clean and chop a whole bunch of mushrooms. I used a food processor for the chopping, which results in a mix of small dice, like duxelles, as well as some larger pieces for texture. I used a pound of standard white button mushrooms and another pound of fresh chanterelles, but any mix of fresh and/or reconstituted dried mushrooms will work, and all-button mushroom is still delicious. After they are chopped, cook them down in a tablespoon of olive oil along with some ground white pepper and some more garlic, as well as some rosemary to taste. I also added in a quarter cup of dry sherry, which is totally optional.
When your mushrooms have cooked down, layer them on top of the bean layer (if you want a less stew-like end product you can drain some of the liquid off of the mushrooms before placing them on top of the beans).
The last step is that rich cheese sauce. To make this, I melted five tablespoons of light butter (this is small concession when you see how much cheese is in this), and whisked in five tablespoons of flour over medium-high heat. When this is combined, gradually whisk in two cups of milk. Low fat or plain soy milk will work, but your sauce will be thinner. Bring this to a low boil and then stir in two cups of shredded parmesan cheese (or romano, or asiago…or, for a vegan version, some nutritional yeast). Remove from heat and whisk in a little ground white pepper, and a pinch of nutmeg. You will notice that no salt has gone into the dish thus far–using canned beans and the aged, grating cheese makes it salty enough, in my opinion, but you can toss a little salt into the mushroom mix if you like. Try it first without.
Pour your sauce carefully over the mushroom layer, and then sprinkle on ANOTHER CUP OF SHREDDED CHEESE. Yep. See why this comfort food?
Put this in the oven, uncovered, and bake at 350 degrees for 45 minutes to an hour. If you want a nicely browned top, run it under the broiler until the top bubbles up and caramelizes (worth it).
Scoop this into some shallow bowls, sprinkle with a little fresh rosemary, and serve with a salad and a nice glass of wine. You will be happy. You will make this again.
Thanks for reading,