A very nice holiday main, this vegan mushroom pie features flakey puff pastry, herbs and spices, and a hint of sweet butternut squash. No vegetarian would be disappointed to have this as their holiday table centrepiece!
I use vegan puff pastry since I can’t eat dairy, and that means this is a fully vegan dish. Ultra savoury and with great texture (no mushy lentil loaf, please) it’s a joy of a meal.
The caramelised onions play an important role here, making up almost half of the filling. The linked recipe calls for red wine to finish the onions and it’s a noticeable flavour note here, so I encourage you to use it.
Vaguely like a giant vegan sausage roll, this is very hearty and very holiday appropriate. I think it’s just as nice for winter holidays and springtime. For some more good veg holiday mains, try out this vegan hot water crust pie, gluten-free stuffed pumpkin, or a mushroom pot pie, also with puff pastry.
Ingredients

Ingredient Notes and Substitutions
- Puff pastry: of course you can sub a butter-based pastry if you prefer, if the dish doesn’t need to be vegan. You could also use the pastry from this potato galette if you prefer not to use puff at all.
- Walnuts: pecans are the best substitution for walnuts, but hazelnuts will work too. For a nut free option I recommend leaving the nuts out rather than subbing with seeds.
- Herbs: change up the herbs as you prefer. I have way too much sage and rosemary in the garden, so I’ve chosen those, but thyme is a very nice addition. A dried blend like herbs de Provence would be good.
- Winter squash: any type of winter squash (barring spaghetti) would work here – don’t feel constrained by butternut.
Step by Step
Start by making the caramelised onions, and take the pastry out to thaw if needed. The onions need two hours plus chilling time and the pastry will need at least four hours to thaw.

1. Prepare the veg: add the mushrooms, squash, walnuts (if using), olive oil, sage, rosemary, salt, pepper, and paprika to a roasting dish. Mix until the vegetables are coated.
2. Bake: bake for 25-30 minutes, or until reduced by about half and the vegetables have golden edges. Set aside to cool completely.
3. Fill: roll out the pastry on a piece of parchment paper. Add the caramelised onions to the centre of the rectangle, then top with the cooled mushroom filling.
4. Roll up: take the edge of pastry closest to you and fold it over the filling, gently pressing with your fingertips to move the pastry under the filling to form a log. Continue to roll the log over to take up the remaining pastry.

5. Seal: use a water dampened pastry brush to brush along the inner edge of where the pastry folds over for a good seal.
6. Form a wreath: gently move the log into a circular shape, bringing the two unsealed ends together. Tuck one inside the other and brush with a little water to seal again.
7. Make steam openings: use the parchment paper under the pastry to slide it carefully onto a large baking sheet. With a sharp knife, cut about nine slits in the top of the wreath.
8. Bake: chill, then bake the pie for 35-40 minutes, or the pastry is a deep golden colour and feels crisp. Cool for about ten minutes before slicing and serving.
Recipe Notes
Most puff pastry is vegan unless it states ‘full butter’ or something along those lines. Just check the ingredient list to make sure. Not the healthiest option, maybe, but so much nicer than a nut roast.
The walnuts are optional (I forgot to add them to the photographed wreath) but add a nice extra layer of texture.
Make sure you use proper caramelised onions, not browned/sauteed onions – they’re a big player in this recipe and it won’t be very good without. For a speedier assembly the day of baking, cook the onions beforehand and refrigerate.
A variety of mushrooms is nice, but not necessary. If you want a really strong mushroom flavour, you could add some rehydrated dried mushrooms into the mix. I’ve used mostly white and brown button mushrooms with shiitake and oyster in smaller amounts.
This is a relatively time consuming recipe in the waiting. The filling needs to be completely cooled before wrapping in the pastry, so again, you may want to make the mushroom filling ahead of time too. As this doesn’t refrigerate as well (cooked mushrooms generally don’t), I recommend making it earlier in the day rather than the day before.
This can be made as a more standard mushroom pie by forming a different shape, rather than a wreath. Think Wellington shape.
How to Store
Storage: leftovers can be refrigerated in a sealed container for a day or two, and are not too bad if reheated in a hot oven, but this is best fresh.
Freezing: I imagine that this can be frozen either before or after baking, but my concern if that the pastry base would become soggy. If I try it I will update this.

Newsletter
Expert Tips
- Chill the elements: everything must be cold before adding to the pastry, and chill the wreath again before baking. If it gets too warm it will lose the flakey texture.
- Prepare in advance: the day before baking, I recommend cooking the onions and thawing the pastry overnight if needed. Otherwise you may end up getting impatient and forming the pie while some things are still warm.
- Cut the slits: this allows steam to escape and will give a nice guide to cut the pastry after baking. Avoid cutting where the seams meet at the circle (as you can see, it’s almost invisible after baking).
- Add an egg wash: optionally, brush the top and sides of the wreath with an egg wash before baking (skip this step if vegan). This will result in a very golden, crispy outer crust.
More Mushroom Recipes
Vegan Mushroom and Pumpkin Shepherd’s Pie
Vegan Mushroom Stroganoff
Lentil Chili
Vegan Stuffed Shells
If you make this Onion and Mushroom Pie or any other vegetarian dinner recipes on Occasionally Eggs, please take a moment to rate the recipe and leave a comment below. It’s such a help to others who want to try the recipe. For more OE, follow along on Instagram, Facebook, and Pinterest, purchase the Occasionally Eggs cookbook, or subscribe for new posts via email.
Caramelised Onion and Mushroom Pie
Ingredients
- 1 package vegan puff pastry
- 1 batch caramelised onions
- 400 grams mixed mushrooms cut into 2cm (3/4 in.) pieces
- ½ medium sized butternut squash peeled and cut into 2cm (3/4 in.) pieces (about 300g)
- 50 grams walnut pieces
- 1 tablespoon olive oil
- 3 sage leaves minced
- 2 teaspoons rosemary leaves minced
- ½ teaspoon sea salt
- ½ teaspoon black pepper
- ¼ teaspoon smoked paprika**
Instructions
- Start by making the caramlised onions, and take the pastry out to thaw if needed. The onions need two hours plus chilling time and the pastry will need at least four hours to thaw.1 batch caramelised onions
- Preheat the oven to 200°C (400°F).
- Add the mushrooms, squash, walnuts (if using), olive oil, sage, rosemary, salt, pepper, and paprika to a roasting dish.400 grams mixed mushrooms, 1/2 medium sized butternut squash, 50 grams walnut pieces, 1 tablespoon olive oil, 3 sage leaves, 2 teaspoons rosemary leaves, 1/2 teaspoon sea salt, 1/2 teaspoon black pepper, 1/4 teaspoon smoked paprika**
- Mix until the vegetables are coated, then bake for 25-30 minutes, or until reduced by about half and the vegetables have golden edges. Set aside to cool completely.
- Once the onions and mushroom filling are chilled, assemble the wreath. Roll the pastry out between two pieces of parchment paper to a rectangle about 40×25 cm (16×10 inch) in size. Keep the bottom piece of parchment paper under the pastry while filling.1 package vegan puff pastry
- Add the caramelised onions to the centre of the rectangle, then top with the cooled mushroom filling.
- Take the edge of pastry closest to you and fold it over the filling, gently pressing with your fingertips to move the pastry under the filling to form a log. Tighten the log as possible but don’t pull or stretch the pastry. Tuck any filling that’s fallen out back in on the sides.
- Continue to roll the log over to take up the remaining pastry. Use a water dampened pastry brush to brush along the inner edge of where the pastry folds over for a good seal.
- Gently move the log into a circular shape, bringing the two unsealed ends together. Tuck one inside the other and brush with a little water to seal again.
- Use the parchment paper under the pastry to slide it carefully onto a large baking sheet.
- With a sharp knife, cut about nine slits in the top of the wreath. This allows steam to escape and will give a nice guide to cut the pastry after baking. Avoid cutting where the seams meet at the circle.
- Preheat the oven to 200°C (400°F) again. Chill the pastry if possible while the oven preheats*.
- Bake the pastry for 35-40 minutes, or the pastry is a deep golden colour and feels crisp. Cool for about ten minutes before slicing and serving.
- Leftovers can be refrigerated in a sealed container for a day or two, and are not too bad if reheated in a hot oven, but this is best fresh.
Notes
* For American cup measurements, please click the pink link text above the ingredient list that says ‘American’.
Nutrition
Nutrition is provided as a courtesy and is an estimate. If this information is important to you, please have it verified independently.

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Margaret Bootz says
My daughter made me this for Christmas and it delicious. She received so many compliments on the presentation and taste. Definitely going to be a keeper for next year’s Christmas or any special occasion.
Emily says
Do you think I could substitute a regular pie pastry for the puff pastry? Thanks 🙂
Alexandra says
Hi Emily! I think that’d be good – the filling is nice no matter what’s around it! It might be a bit tricky to get the wreath shape with regular pastry but you could do it in a pie form, too.
Emily says
Ok great, thanks! Excited to give this a try 🙂
chris says
Can i bake this ahead and freeze?
Alexandra says
Hi Chris – I think you’d be better off freezing before baking, then thawing in the fridge before baking. I’m not 100% sure but think that would give you a better result.