Cook the cabbage leaves: Bring a large pot of salted water to a rolling boil. Have a large bowl of ice water ready off to the side.

Drop the leaves into the boiling water and blanch just until pliable, 1–2 minutes. Don’t overcook or you will lose the bright green color. Immediately transfer cabbage leaves to the bowl of ice water to stop the cooking. Drain the cabbage and pat dry with paper towels. Set aside.

Cook the butternut squash: Heat oven to 400°F.

Using a sharp vegetable peeler, remove the skin from the squash. Cut the squash in half lengthwise, scoop out the seeds and dice the flesh into 1-inch cubes. Try to keep the pieces uniform in size for even roasting. Add to a bowl and toss with a drizzle of olive oil, and salt and pepper to taste. Add maple syrup, smoked paprika and fresh herbs, if you like, to taste.

Place the squash in a single layer on a parchment-lined baking sheet. Roast until the edges are golden and the squash is tender when pierced with a fork, 25–35 minutes, flipping the squash pieces halfway through. Let cool.

Prepare mushroom duxelles: Clean and dry the mushrooms. Remove and discard any tough stems. Finely chop the mushrooms with a knife or use a food processor to get a texture close to a coarse paste.

In a skillet, melt the butter over medium heat. Add the shallot and 3 cloves minced garlic; sauté until soft and translucent, about 2 minutes. Stir in the mushrooms and thyme. Cook over medium to medium-high heat, stirring often, until the mushrooms release their liquid and it fully evaporates, 10–15 minutes. Add a splash of wine or sherry and let it cook off completely. Stir in the heavy cream, if using. Season to taste with salt and pepper. Let cool.

Cook the spinach: Rinse spinach leaves well and shake off excess water. It’s not necessary to dry completely, as a little moisture helps the leaves wilt when cooked.

In a large skillet, heat the 1 tablespoon olive oil over medium heat. Add the remaining 3 cloves minced garlic and sauté for about 30 seconds, until fragrant (don’t brown it). Add spinach in batches, turning with tongs until just wilted, about 2 to 3 minutes. Season with salt, pepper and a squeeze of lemon juice.

Line a small bowl (about 6- to 7-inches in diameter and about 3 inches tall) with plastic wrap. Next, line with 1 or 2 blanched cabbage leaves.

Divide the butternut squash, mushroom duxelles and spinach into three equal portions. Layer the portions into the bowl over the cabbage leaves, beginning with the mushrooms, then the spinach, then the butternut squash. Fold any overhanging cabbage leaves over the top, trimming to fit nicely.

On a lightly floured surface, roll out 1 sheet of puff pastry to about 1/8-inch thickness. This will be the bottom of your pithivier. With a round cutter or a plate as a guide, cut out a circle (about 10–12 inches in diameter) from the pastry and transfer to a baking sheet lined with parchment paper.

Invert the bowl of filling onto the center of this puff pastry circle. Remove the plastic wrap.

Roll out a second sheet of puff pastry in the same manner as the first. Place this second pastry circle over the filling. Press down on the pastry to form a tight seal around the filling. Then crimp or twist the edges to seal well.

Cut a few slits or a small hole in the center of the top pastry to allow steam to escape during baking.

Repeat with the rest of the filling and pastry until you have 3 pithiviers. If the puff pastry gets too soft at any point, refrigerate for a couple of minutes until firm before proceeding with the recipe.

Brush the beaten eggs over the top of each pastry.

Place the pithiviers in the oven and bake until the pastry is golden brown and puffed, 25–30 minutes.

Remove from the oven and let rest for about 10 minutes before slicing. Serve warm with a salad. Makes 3 pies; serves 3 to 6.