Roasted Squash and Red Onion Gratin with Quinoa

Recipe by Martha Rose Schulman for the New York Times

6 servings

1 1/2 lbs. kabocha squash, peeled, seeded and membranes removed, and cut into a small dice (1/2 to 3/4 inch).  About 4 cups diced total.
2 Tablespoons olive oil
salt and pepper, to taste
1/2 red onion, chopped
1 leek, white and light green parts only, cut in half, cleaned and chopped (we don’t have them yet at the farm so I omit it with fine results, but if you have access to a leek, use it!)
2 garlic cloves, minced
2 teaspoons fresh thyme
1/2 cup grated parmesan
3 eggs
1/2 cups milk
1/2 cup cooked rainbow or black quinoa

Preheat your oven to 425°.  Cover a baking sheet with parchment or foil.  Toss the squash with 1 Tablespoon olive oil and season with salt and pepper.  Spread on the baking sheet in an even layer.  Roast for 30 minutes, stirring every 10 minutes or so, until tender and caramelized.    Remove from the oven and turn the heat down to 350°.  
While the squash is roasting, heat the remaining olive oil in a medium skillet and add the onion.  Cook for about 3 minutes, until the onion begins to wilt.  Add the leek and a generous pinch of salt and cook, stirring, until the onion and leek are tender (3-5 minutes).  Add the garlic and thyme, and cook for about 30 seconds.  Remove from heat.
Oil a 2 quart baking dish or gratin.  In a large bowl, beat the eggs and add a bit of salt and pepper (about a 1/2 teaspoon).  Whisk in the milk.  Add the onion/leek mixture, squash, parmesan and quinoa and combine well.  Scrape into the prepared baking dish.  Bake for 35-40 minutes, until set.  Allow to cool for 10 minutes or longer before serving.