This is the easiest and tastiest way to make roasted portobello mushrooms!
I love the meatiness of roasted Portobello mushrooms but sometimes I just don’t have the time or inclination to marinate them before roasting them in the oven. Luckily, there’s a quick and dirty method that does the trick.
Once these ‘shrooms are roasted, I slice them up and drizzle on my favorite vinegar or spritz on some lemon or lime juice. Voila! Easy and tasty side dish! Alternatively, you can use the caps as “bread” for Paleo sandwiches since they come out nice and flat.
Time to make Roasted Portobello Mushrooms!
Serves 4
Ingredients:
- 4 large Portobello mushrooms, wiped clean with a damp cloth or paper towel
- melted ghee, melted coconut oil, or your favorite fat
- Kosher salt
- Freshly ground pepper
- Sunny Paris seasoning or your favorite chopped fresh herbs (optional)
- Lemon or lime juice or your favorite vinegar
Equipment:
- All of my recommended kitchen tools are listed here.
Method:
Preheat the oven to 400°F and place an aluminum foil-lined rimmed baking sheet on the middle rack.
Grab the mushrooms, remove the stems…
…scrape out the gills with a spoon…
…and flip the caps gill-side down.
Cut a shallow “X” on the top of each mushroom…
…brush the whole cap (top and bottom) with melted fat…
…and season both sides with salt and pepper.
Sprinkle Sunny Paris seasoning on the caps before sticking them on the hot baking tray in the oven, gill-side up.
After 10 minutes of roasting, flip the mushrooms and then cook them for an additional 10 minutes (20 minutes total).
When the mushrooms are done roasting, slice them up and squeeze on some lemon juice. (If you are adding minced fresh herbs, do it now!)
Or you can keep them whole and use them as hamburger buns for Big-O Bacon Burgers or Nomster Burgers!
Easy and tasty – just how I like it!
Looking for more recipe ideas? Head on over to my Recipe Index. You’ll also find exclusive recipes on my iPhone and iPad app, and in my cookbooks, Nom Nom Paleo: Food for Humans (Andrews McMeel Publishing 2013), Ready or Not! (Andrews McMeel Publishing 2017), and Nom Nom Paleo: Let’s Go! (Andrews McMeel Publishing 2021).
PRINTER-FRIENDLY RECIPE CARD
Roasted Portobello Mushrooms

Ingredients
- 4 large Portobello mushrooms wiped clean with a damp cloth or paper towel
- Melted ghee melted coconut oil, or your favorite fat
- Kosher salt
- Freshly ground pepper
- Sunny Paris seasoning or your favorite salt-free herb blend
- Lemon or lime juice or your favorite vinegar
- Minced fresh herbs optional
Instructions
- Preheat the oven to 400 F and place an aluminum foil- or parchment-lined baking sheet on the middle rack.
- Grab the mushrooms and remove the stems, scrape the gills out with a spoon, and flip the caps gill-side down.
- Cut a shallow “X” on the top of each mushroom, brush the whole cap (top and bottom) with melted fat, and season both sides with salt and pepper.
- Sprinkle some Sunny Paris seasoning (or your favorite salt-free herb blend) on the caps before sticking them on the hot baking tray in the oven, gill-side up.
- Roast the 'shrooms for 10 minutes, and then flip them over to cook for an additional 10 minutes (20 minutes total). If you're using the cooked caps as buns, you're done!
- If you're serving the 'shrooms as a side dish, slice them up and squeeze on some lemon juice and minced fresh herbs.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Delicious and simple! Perfect for a Whole 30. I served mine with a side salad. I only wish I would have doubled the recipe! Nomnom paleo recipes never stir me wrong.
How long would these mushrooms last after cooking in the fridge?
About 4 days in the fridge.
I LOVE roasted Portobello, so I can’t wait to try these! And thank you for tip on the Sunny in Paris seasoning. It sounds like an amazing spice blend – definitely heading to a Penzey’s to pick it up! One question, do you need to do anything special for the caps if you are using them for buns? Mushrooms have so much water in them, I would be afraid they would come out too wet to handle.
Portobellos aren’t too waterlogged—just make sure you roast until most of the moisture has been baked off.
Why do you need to remove gills?
It keeps the mushrooms from discoloring and makes them taste better (in my opinion).