French Collard Greens, Melted Onions, and Mushroom Pie

Directions

1. Heat a large cast iron skillet over medium heat. Add a good glug of olive oil and the onions. Sauté, stirring occasionally until onions soften, about 5-7 minutes.
2. While the onions cook, chop the collard stems into 1/4-inch segments, and roughly chop the leaves. Set aside.
3. Add the mushrooms to the pan. Season with sea salt and freshly ground pepper, and sprinkle in half the nutmeg. Stir to incorporate and add a little more olive oil if needed. Sauté for 5-7 minutes more, or until mushrooms give up their liquid. Pour mixture into a large bowl and set aside.
4. Add another glug of olive oil and the chopped collard spines to the pan. Brown lightly, stirring occasionally, for 5 minutes over medium-high heat. Add the chili powder and 1/2 the beer (it should sizzle as it hits the pan), stir, and season with sea salt and freshly ground pepper.
5. After a couple more minutes, add the chopped collard leaves and the garlic. Stir to incorporate. Add the remainder of the nutmeg and beer, lower heat to medium, and cook just until the leaves soften, about 3-5 minutes. Remove pan from heat.
6. Roll out one sheet of puff pastry on a lightly floured surface, and using an 11" tart ring, cut out a circle (save scraps for another use). Place circle on a parchment-lined baking sheet and refrigerate.
7. Roll out the second sheet of puff pastry into a square and gently drape over the tart ring, on another parchment-lined baking sheet.
8. In a bowl, stir together the toasted walnuts, 3/4 of the cheese, and collards mixture. Carefully spoon mixture into the pastry. Spread an even layer of the mushroom-onion mix on top and scatter the last bit of cheese. As the mushroom mixture was more wet, I found that adding it to top the other ingredients made for less liquid seeping through the pastry.
9. Lay the pastry circle on top and trim the bottom pastry to 1-inch border beyond the ring. Wet the edge of the circle with water and tuck the bottom over the top using a twisting motion for a braided edge look. Remove the pastry ring and chill in the refrigerator for a minimum of 30 minutes. While pastry is chilling, preheat oven to 350 degrees (F).
10. Lightly beat the egg and paint the pastry all over with eggwash. Bake for 30-45 minutes, until the pie is golden brown all over. Cool for ten minutes on a wire rack and dig in.