Squash Puff

• 2.5 pounds mashed butternut squash (or 3 cups)
• 3 tablespoons unsalted butter, divided
• 1/4 cup finely minced white onion
• 2 eggs, separated
• 1/4 cup milk
• 3 tablespoons all purpose flour
• 3 teaspoons baking powder
• 3/4 teaspoon salt
• 1/8 teaspoon freshly ground black pepper
• 1/2 cup unseasoned bread crumbs

1. Preheat oven to 375 F. Grease a 6-cup casserole dish.
2. Prepare buttered breadcrumbs. Melt 1 tablespoon of butter in a frying pan over medium-high heat. Add unseasoned bread crumbs and stir until butter is absorbed. Remove from heat and set aside.
3. Melt the remaining 2 tablespoons of butter into a clean frying pan, and saute the minced onion until translucent.
4. Stiffly whip the egg whites. Set aside.
5. In a large bowl, combine the pureed butternut squash with the sauteed onions. Add the egg yolks, milk, flour, baking powder, salt and pepper, stirring to combine.
6. Quickly fold the stiffly beaten egg whites into the butternut squash batter.
7. Pour batter into the greased casserole pan, smoothing top. Sprinkle with the buttered bread crumbs.
8. Bake for 25 minutes. When cooked, the edges will be golden brown and pulling away from the dish. The center will have puffed up.
9. This recipe can be prepared the day before and reheated, covered, in a 200 F oven until warm. It won't maintain the puffed appearance but will be just as tasty.

butternut squash, unsalted butter, white onion, eggs, milk, flour, baking powder, salt, freshly ground black pepper, bread crumbs

Taken from food52.com/recipes/7335-squash-puff (may not work)