Vegan Portobello Steak Frites 

Steak and potatoes got a super gorgeous make over!  

Vegan portobello steak frites. Yes. For Real. This is delicious. Juicy roasted portobellos that are marinated in all kinds of amazing things that make them taste “steaky”, crispy french fries and I highly recommend serving with my oil free roasted red pepper chimichurri! These mushroom steaks get so crazy yummy in the oven after being marinated. I like to marinate them over night. Which makes this the quickest, easiest recipe ever. 

Not only is this portobello steak frites perfect for the oven, you can totally grill these “steaks” so it is a great recipe for all year! The marinade for the mushrooms should be fairly easy to find ingredients, most of which you probably have on hand. 

I love to throw all of the marinade ingredients into a freezer bag, then add the mushrooms. That way you can make sure they are fully submerged the whole time. You can marinate them anywhere from 2 hours to over night, but the longer the better. The marinade has liquid smoke and A-1 steak sauce and let me tell you, it smells epic.

There are so many toppings and sauces that would be great with this portobello steak frites, but let’s talk about my roasted red pepper chimichurri sauce. I made it oil free to lighten it up, replacing the oil with veggie broth. Then it has all the classic chimichurri ingredients with the addition of roasted red peppers. It is outrageous! 

Throw the mushroom steaks and fries in the oven, and you are only 20 minutes away from one of the best dinners of your life! Sauce adapted from my Lightened up Chimichurri sauce!

Vegan Portobello Steak Frites
Prep Time
15 mins
Cook Time
25 mins
Total Time
40 mins

Steak marinated portobellos roasted with french fries and topped with  oil free roasted red pepper chimichurri!

Course: Main Course
Servings: 4
Author: Lauren Hartmann
  • 6 oz. Portobello mushrooms, 2 large or 4 small
  • 1 C. Vegetable broth
  • 1 Tbsp. Olive oil
  • 1 Tbsp. Steak sauce, vegan I used A-1
  • 2 tsp. Liquid smoke
  • 2 Tbsp. Soy sauce
  • 2 Cloves Garlic, chopped
  • 1 Bag Frozen french fries
Roasted Red Pepper Chimichurri
  • 1/2 C. Cilantro, fresh
  • 1/2 C. Parsley, fresh
  • 1/3 C. Roasted red peppers
  • 2 Cloves Garlic
  • 2 Tbsp. Red onion
  • 1/4 C. Vegetable broth
  • 1 tsp. Red wine vinegar
  • Juice of 1 Lemon
  • Salt and pepper to taste
  1. You first want to marinate the portobellos. Add the veggie broth, olive oil, steak sauce, liquid smoke, soy sauce and chopped garlic to a large freezer bag that seals really well. 

  2. Then place the portobellos into the bag, seal and shake around to coat the mushrooms completely. Lay them flat so they are submerged in the marinade. Marinate for at least 2 hours, but I like to leave them over night. 

  3. When you are ready to cook the mushrooms, preheat the oven to 425 degrees. 

  4. Remove the mushrooms from the bag and place them on a baking sheet. Then place the french fries on a separate baking sheet, because the mushrooms will get super juicy and you don't want the fries to soak in the juice. 

  5. Bake the mushrooms and fries at the same time. Bake the mushrooms for 20-25 minutes flipping halfway through baking. Check the directions on your fries for timing, but they most commonly will bake at 425 for about 20-25 minutes as well!

  6. While the mushrooms and fries are baking, make the roasted red pepper chimichurri sauce. Add all the sauce ingredients to a blender or food processor. Blend until smooth. add a few pinches of salt and pepper. Taste and adjust seasoning. 

  7. Once the mushrooms and fries are done, serve immediately topped with sauce. 

Recipe Notes

If your mushrooms are too large to be submerged in the marinade, just toss them around every once in a while to make sure the marinade is evenly distributed. 

These "steaks" would also be great just topped with steak sauce, a horseradish sauce, or really anything your heart desires. 

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  • Reply
    October 11, 2018 at 3:02 am

    Do you leave the mushrooms overnight in the fridge or on the counter?

    • Reply
      Lauren Hartmann
      October 14, 2018 at 11:18 pm

      I usually put them in the fridge!

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