GEEZ, I must have made this five times before it got close to right. It started because I have all these great pasta with vegetable pesto recipes from last fall and I'm not eating pasta this fall, but the vegetable pestos are really easy and good, and potato and sweet potato are doing starch duty, so I thought what could be easier and more delicious than layering potato or sweet potato with vegetable pesto in a gratin. Well it's easy now, everything is tweaked and it all works. And it is delicious. It's not the prettiest dish in the world, it's what I call space food—a perfect balance of starchy vegetable and vegetable that can be reheated and scarfed down an hour before practice. Because obviously astronauts eat gratins in space, haha, all the layers floating apart, but what I mean is it's sort of engineered nutrition.
1 lb frozen cauliflower
2 cloves garlic
1/2 cup walnuts, toasted
1/2 cup grated parmesan cheese
1/4 teaspoon ground cayenne
1 cup almond milk
4 sweet potatoes
1/4 cup butter
a bit more almond milk
another 1/4 cup of parmesan cheese
Heat oven to 500 degrees.
Bring water to a boil over high heat in a large saucepan. Add cauliflower and cook until tender, about five minutes. Drain.
Put the cauliflower, garlic, walnuts, parmesan cheese and cayenne into a food processor and process until roughly chopped. Add the almond milk and process until incorporated, you don't want it to be perfectly smooth. I mean, unless you do.
Peel and slice the sweet potatoes very thinly. Melt some butter in the microwave and get your brush. First brush your ovenproof skillet with butter, then lay down a layer of sweet potatoes and brush them with butter. Spread some cauliflower pesto over the buttered sweet potatoes, not too thick. Lay down another layer of sweet potatoes, brush with butter, and spread with pesto, you do this three more times. After the fifth layer of potatoes though, you should have just a little bit of pesto left. Mix that with whatever butter's leftover and a bit more almond milk and brush that all over the top layer, then sprinkle over a final layer of parmesan cheese.
Bake for forty minutes until the top is golden brown and the sweet potatoes are very tender when poked with a fork. Let cool a bit before slicing, then the slices come out better.