Don’t you just love some good, tangy, smokey BBQ? I sure do. Combine that with a love of caramelized mushrooms and onions, and you’ve got this simple, scrumptious Oven-Roasted BBQ Mushroom Sandwich. (No worries—if you’re a mushroom hater, you’ve got options here, too!)
What I Love About this BBQ Mushroom Sandwich
I love this BBQ mushroom sandwich recipe because it completely satisfies my cravings for barbecue, and it features an unsung hero of a veggie—the mighty white mushroom! White mushrooms are easy to find, inexpensive and have surprising health benefits.
For example, of all vegetables, white mushrooms have been shown to be the most effective in helping prevent breast cancer. In fact, of the mushroom varieties, the common white mushroom outranked them all for this important health benefit. This alone has me wanting to work mushrooms into my diet on a regular basis.
And the smell of these mushrooms and onions roasting together in the oven in their own juices? Granted, I’m a mushroom lover--but it’s to die for! It reminds me of the mushrooms my Mom used to make, loaded with butter and sautéed until they were dark brown and chewy. Fantastic! Of course these are much, much healthier.
How to Make this Sandwich
This recipe really couldn’t be simpler. We start by spreading out some sliced mushrooms and onions on a couple baking sheets, adding a bit of salt and pepper, and popping them into the oven. I bought pre-sliced mushrooms to make things even quicker.
Then, while these veggies are roasting, we make a simple vegan barbecue sauce (if you’re not using store-bought), and a quick and easy purple cabbage slaw. Each one of these elements comes together in just a few minutes—so when your mushrooms and onions are done, you can just put everything for your BBQ mushroom sandwich together.
You can use a store-bought BBQ sauce, but I find the healthiest, refined-sugar free option usually means making your own. But no worries—this easy vegan barbecue sauce recipe is a breeze.
It’s made with with ingredients you probably have on hand in your pantry and use on a regular basis. Nothing exotic here! And you can whip it up in one bowl in five minutes.
Same goes for the purple cabbage slaw. You whip it up in a single bowl, and most of the prep time is passive marinating with a bit of tossing. It adds a nice, light crunch to this BBQ mushroom sandwich, with a touch of heat if you include the optional jalapeno peppers or some creaminess if you choose the version made with oil free vegan mayo.
What if I Don’t Like Mushrooms?
Every time I post a recipe with mushrooms, I get comments from folks who just can’t tolerate them. So for this BBQ recipe, I have an alternative version you can make with lentils. It will still be great—and full of fiber. In fact, I plan to mix it up and make this with lentils myself sometimes, even though I LOVE mushrooms.
Smokey, saucy, tangy, spicy, crispy, healthy—this BBQ mushroom sandwich brings it all.
If you like this whole food plant-based recipe, you might also like:
- Sweet & Spicy Grilled Eggplant
- Vegan Portobello Mushroom Burger with Cheddar Sauce
- Vegan Barbecue Sauce - Easy & Homemade
- Best Damn Vegan Chili
- Best Damn Instant Pot Vegan Chili
- Vegan Mushroom Walnut Bolognese
📖 Recipe

Oven-Roasted BBQ Mushroom Sandwich
Ingredients
- 1 pound sliced white button mushrooms (or sub creminis/baby bellas. Or sub lentils - see notes.)
- 1 yellow onion cut in ½ and sliced into ¼ inch thick pieces
- Sea salt and black pepper to taste
- ¾ cup Vegan BBQ Sauce (or more for a saucier sandwich. Or sub store-bought sauce like Annie's Naturals)
- 4 whole grain buns (GF if desired)
Purple Cabbage Slaw
- 2 cups purple cabbage shredded (about ½ small head)
- 1 cup carrots shredded (about 2 carrots)
- ½ cup vinegar apple cider or rice vinegar work well
- 2 teaspoons maple syrup
- Freshly ground black pepper to taste
- ½ teaspoon celery salt (or sub celery seed to reduce sodium)
- Optional: 1-2 jalapeno peppers sliced (if you like heat)
- Optional: 2 Tablespoons Oil Free Vegan Mayo for a creamy slaw - see notes
Instructions
- Preheat the oven to 400 degrees Fahrenheit. Line 2 baking sheets with parchment paper. (See notes)
- In a large bowl, toss the sliced mushrooms and onions with salt and pepper. Spread the veggies in an even layer on two baking sheets, and bake for 25 minutes, or until the mushrooms and onions are golden brown. Turn over after 15 minutes.
- While the mushroom and onions are roasting, make your BBQ sauce (if using homemade) and your slaw.
- To make the purple cabbage slaw: toss everything together in a medium mixing bowl, and allow to marinate for at least 15 minutes or more. Toss every 5 minutes or so.
- Place the roasted mushrooms and onions in a medium mixing bowl, and toss with ¾ cup (or more!) of the BBQ sauce. Heat gently in a sauce pan over medium heat.
- Place ¼ of the BBQ mushrooms and onions on each bun, and serve with pickled purple cabbage slaw as a topping or on the side.
Victoria
Can't wait to make this! I love bbq but not always the meat that goes with it. And the pickled slaw...perfect accompaniment! Thanks!
Jen
Thanks for adding the sauté method too! It’s definitely too hot in our house to use the oven this week.
Elizabeth Shah
Hi Jen, You're most welcome! It's hot where I am too--111 degrees this week :0