Winter Squash-and-Onion Tart

 

3 T. butter, divided

1 large sweet onion, halved and sliced

1 refrigerated piecrust

2 cups mashed or pureed butternut squash (from about 1 pound cubed)

2 large eggs

½ cup (2 ounces) grated Havarti, fontina, or Gouda cheese

¼ cup shredded Parmesan cheese

2 ounces soft goat cheese, crumbled

1 tsp. chopped fresh rosemary

½ tsp. salt

¼ cup panko breadcrumbs

¼ tsp. freshly ground black pepper

 

Melt 2 T. butter in a skillet over medium heat. Add onion and cook 30 to 35 minutes or until golden brown and very tender. Set aside. Preheat oven to 375°. Unfold piecrust and fit into a 9½-inch tart pan with removable bottom. Line the bottom with aluminum foil, and fill with pie weights, uncooked rice, or dried beans. Bake 15 minutes. Remove foil and weights; bake 5 more minutes. If using cooked cubed butternut squash, mash until smooth. Whisk in eggs, cheeses, rosemary, and salt. Stir in onion. Spread squash mixture into pastry. Melt remaining 1 T. butter. Stir in panko and pepper. Sprinkle over squash. Bake 40 minutes or until golden brown and set. Cool 5 minutes before slicing.