This Mushroom Wellington with caramelized onions, spinach and sliced sweet potatoes is an elegant vegan main dish for holidays. Packed with savory flavors and easy to make!
Other lovely plant-based main dishes to make for a holiday include Vegan Wellington (more of a meaty base), Lentil Loaf, Butternut Squash Lasagna and Mushroom Bourguignon.
From Vegan Turkey Roast to glazed Vegan Ham, there’s no shortage of show-stopping holiday main dishes available on my blog. But if you’re looking for something impressive with plants front and center, you’ll love this easy Mushroom Wellington recipe.
It’s similar to my meaty Vegan Wellington but swaps the vegan beef filling for a beautifully seasoned filling made from whole foods, like herb-dressed mushrooms, caramelized onions, spinach, and sliced sweet potatoes. The filling is a breeze to make in one skillet and takes minutes to wrap in a layer of vegan puff pastry.
Baked until crisp and golden, then sliced and served with vegan gravy, this is one vegan holiday main dish that’s guaranteed to please everyone at your Thanksgiving or Christmas dinner.
Why I love this mushroom wellington
- An easy holiday main or side dish – This vegetable wellington is nowhere near as complicated as a classic beef wellington. Making the caramelized onion and mushroom filling is foolproof and wrapping it in the puff pastry couldn’t be easier!
- Nourishing and wholesome – A lot of vegan wellington recipes are made with a vegan ground beef filling. While that is delicious, this recipe showcases nourishing whole foods in the filling instead, like mushrooms, spinach, sweet potatoes, and onions.
- Buttery puff pastry – It just wouldn’t be a wellington recipe without the buttery, golden, and flaky puff pastry!
How to make mushroom wellington
Set the frozen puff pastry on the kitchen counter to let it thaw. While you wait, start the filling by pulsing the mushrooms in a food processor until they’re crumbly.
Warm the olive oil in a large skillet over medium heat. Add the sliced onions and cook until they’re caramelized*.
*The onions can take between 30 to 45 minutes to caramelize, so be patient! As they take on a deep golden brown color, they become incredibly rich and flavorful.
Add the chopped mushrooms, garlic, and soy sauce to the skillet. Cook until the mushrooms have softened and most of their liquid has evaporated.
Next, stir in the thyme, rosemary, and baby spinach and cook until the spinach wilts.
To start assembling the vegetarian wellington, roll out the thawed puff pastry sheet on a parchment-lined baking pan and add a layer of thinly sliced sweet potatoes to the middle third of the pastry.
Add half the mushroom mixture on top, then top with another layer of thinly sliced sweet potatoes.
Dump the rest of the mushroom filling on top, then finish with a final layer of sweet potatoes.
Fold the sides of the pastry over the top of the mixture and pinch the edges to seal them closed. You can use a little water on your fingers to help them seal if needed.
Score the top of the wellington in a criss-cross pattern to encourage steaming.
Next, stir the olive oil and milk in a bowl, then brush it over the tops and sides of the wellington. This vegan “egg wash” helps the pastry become crisp and golden brown.
Bake the mushroom wellington until the pastry is golden and puffy. Set it aside to rest for at least 10 minutes, then slice and serve with lots of vegan gravy. Enjoy!
Frequently asked questions
Yes, most store-bought frozen puff pastry is vegan-friendly! I like using Pepperidge Farm puff pastry because it’s delicious and really easy to work with. You should be able to find it or similar brands in the frozen section at most major grocery stores.
I like making the filling with cremini mushrooms but you can use any other kind of mushroom you like, such as wild mushrooms, portobello mushrooms, chestnut mushrooms, baby bella mushrooms, etc.
There are a few ways to put your own spin on the filling. You can (1) deglaze the skillet with a splash of dry white wine when you add the mushrooms for a light citrus flavor, (2) caramelize shallots and/or leeks along with the onions, and/or (3) add chopped walnuts to the mushroom mixture for a soft crunch.
Yes, you can fully assemble the wellington up to 1 day before baking and serving. Just wrap it in a layer of plastic and keep it in the fridge.
Alternatively, you can slice the sweet potatoes and make the mushroom filling 1 to 2 days before assembling and baking the vegetarian beef wellington. Keep them in separate airtight containers in the fridge. Also, feel free to thaw the puff pastry in the fridge the night before you make this recipe so you don’t have to wait for it to thaw.
The leftover wellington slices can be stored in an airtight container in the fridge for 3 to 4 days or in the freezer for about 2 months. Keep in mind that the pastry will get a bit soggy over time. Reheat the slices in a 350ºF oven until warmed through and the pastry is crisp.
Thaw puff pastry and preheat oven
Set the frozen puff pastry out to thaw while you prepare the filling. It will take about 30 minutes to thaw.
Preheat the oven to 375 degrees F and lightly grease a baking pan.
Prepare the mushroom filling
Add the mushrooms to a food processor and pulse several times until crumbly, but be careful not to over process them. Alternatively, chop them small with a large knife.
Warm the olive oil in a large pan over medium heat. Add the sliced onions and cook for about 30 minutes, stirring every few minutes, until caramelized. They should be golden brown in color.
Add the chopped mushrooms, garlic and soy sauce and cook for about 10 minutes, until the mushrooms have softened and the liquid released from the mushrooms has mostly evaporated.
Add the thyme, rosemary and baby spinach. Stir well to combine as the spinach wilts. Remove from heat.
Assemble wellington and bake
Once the puff pastry has thawed, roll it out to about 9×12 inches on a piece of parchment paper (this will make it easier to turn over onto the pan).
Add a layer of thinly sliced sweet potatoes to the middle third of the pastry. Top with half of the mushroom mixture, then add another layer of sweet potatoes. Add the rest of the mushroom mixture, then finish with a final layer of sweet potatoes. (see photos above in post for reference)
Fold the sides of the pastry over the top of the mixture and pinch and seal the edges. Use a little water on your fingers to help it seal if needed.
Carefully roll the wellington over onto the pan, using the parchment paper to help, so the seam side is down.
Use a sharp knife to score the dough in a criss cross pattern.
In a small bowl, stir the olive oil and milk to combine, then brush the tops and sides of the wellington with it.
Bake for 40-45 minutes, until golden brown and puffy. Let it rest for 10 minutes before slicing. Serve with vegan gravy and enjoy!
- Make ahead – You can prepare this a day ahead of time and store in the refrigerator until ready to bake. Or make the filling and slice the sweet potatoes ahead of time, store in the refrigerator, then thaw the puff pastry, layer and bake.
- How to store leftovers – Keep any leftovers in a covered container in the refrigerator for 3-4 days. You can also freeze some of it if needed.
- Mushrooms – I used cremini, but you can use basically any mushroom you like. Slice them instead of chopping if you want more texture.
Serving: 1of 8 servings | Calories: 294kcal | Carbohydrates: 32g | Protein: 5g | Fat: 17g | Saturated Fat: 4g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 10g | Sodium: 266mg | Potassium: 391mg | Fiber: 3g | Sugar: 5g | Vitamin A: 9351IU | Vitamin C: 10mg | Calcium: 53mg | Iron: 2mg