Butternut Squash Au Gratin with Crispy Shallots
1 pound of shallots (about 2 cups thinly sliced)
1/2 cup oil of choice for frying (I like to use organic Spectrum Palm Oil)
Approx 5 lbs of whole butternut squash (about 2 lbs once sliced)*
1 1/2 cups cashews, soaked for 2-4 hours, then drained
1 1/4 or more cups canned coconut milk, water or chicken broth
4-5 roasted garlic cloves (instructions below)
1 teaspoon coarse sea salt, plus 1 tablespoon more for sprinkling
Fresh ground pepper for sprinkling
A little olive oil to brush on top of the au gratin
Note: *When buying the butternut squash, it is best to buy ones that have a very long neck. This will help you get more full circles out of the squash. Often times I buy more squash than I need so that I have whole circles for the entire dish (saving the end ‘hollow’ pieces for a breakfast hash) However, it is fine to use the squash pieces with a hole in the center also.
1. Pre-heat oven to 375 degrees
2. Begin by peeling the butternut squash with a vegetable peeler. I use a strong stainless steel one since the outer skin can be quite tough. Cut off the fat “hollow” end and very thinly slice the squash with a mandolin veggie slicer set on the 1/8 inch setting. Set the squash aside.
Pro Tip: I like to pull out a some of the best squash slices for the top layer of the au gratin.
3. Using the mandolin veggie slicer or sharp knife, thinly slice the shallots.
4. Pre-heat the oil in a large frying pan over medium heat for 1-2 minutes then add the shallots to the oil. Gently fry for about 20 min. You want the shallots to brown SLOWLY. If the oil gets too hot and they start to brown too fast or unevenly, turn the heat down a little. Watch them closely.
5. Once the shallots are golden, remove them from the pan with a slotted spoon. Let them drain for a moment, then let them cool on a paper towel. Sprinkle with a little salt. They will become crispy as they cool. Note: Crispy shallots can be made up ahead of time and stored in an airtight container for a few days and sometimes even longer. They are also a huge flavoring component to this dish.
6. Now you can put together the cashew sauce. (Alternately, you can also use my White Wine & Thyme Cashew Gravy recipe, it’s amazing in this!) In a blender, add the cashews, coconut milk (water or broth), roasted garlic* and 1 tsp of salt. Puree until the mixture is creamy. Stop and stir as needed to keep it moving through the blender. Add more liquid, 1 tablespoon at a time if needed.
*To make roasted garlic in a pan, just take the cloves still in their paper and heat them in a pan over medium heat. Let them ‘roast’ this way for about 15 minutes, turning every so often to ensure even cooking. It’s ok for the paper to burn some. Remove from heat, let cool, then take off the paper skin.
7. To assemble the au gratin, spread about 1/4 cup of the cashew mixture on the bottom of a small 7 x 10 casserole dish. Then lay down your first layer of thinly sliced squash. The squash should overlap slightly, but not too much or you will not have enough to do all of the layers. Note: I use a 7 x 10 Le Creuset casserole dish, If you want a larger au gratin you can double the recipe easily.
8. Spread another 1/4 cup of cashew sauce over the first layer. Sprinkle very lightly with coarse sea salt, cracked pepper, and shallots evenly over this layer. Repeat this for the rest of the layers until you run out of squash, finishing the top layer with the best squash slices of course.
9. Using a pastry brush, brush the top of the au gratin with a light layer of olive oil (or oil of choice). Sprinkle lightly with coarse sea salt and cracked pepper then bake in the oven for about 35-40 minutes or until the top is lightly browned and crispy in parts. If the au gratin doesn’t crisp to your liking, you can broil the top for few minutes or go over it with a torch till browned to your liking.
Have leftovers? This dish reheats well in a 375-degree oven for about 25 minutes.