Portobello Steaks with Avocado Chimichurri

Friends, welcome to grilling season.

I know what you’re thinking. Here we go with the fake meat substitutes and crumbly veggie burgers.

But not so fast! Here’s my new, go-to plant-based option: Grilled portobello mushrooms in a saucy marinade with spicy avocado chimichurri.

Marinating mushrooms for Grilled Portobello Steaks

This recipe is inspired by my absolute favorite veggie burger at the moment, which is in our (new and improved, entirely plant-based31 Meals eCookbook!

They take about 30 minutes and are insanely easy to make. Just marinade, make your chimichurri, grill the mushrooms, dig in. It’s go time.

Whisking together ingredients for Avocado Chimichurri

When I was first conceiving recipe, I thought chimichurri* – a citrusy, classic “steak” sauce with loads of parsley – would be a perfect pairing. And when I tasted it, I knew something was missing. Avocado to the rescue for seriously buttery texture and loads of nutrients.

Oh avocado, what can’t you do?

Cooking Portobello Steaks in a cast iron skillet for a healthy plant-based summer meal

These steaks are great on the grill or on the stovetop! I personally prefer a cast iron skillet since the entire surface gets browned and caramelized.

I hope you LOVE these steaks! They’re:

Buttery from the avocado
Extremely nutritious
& SO easy

This is the perfect option for all your summer grilling needs. They’re great on their own but would also pair well with salads, mashed potatoes, or cooked quinoa or rice (links below!).

Using a fork to cut into a Grilled Portobello Steak with Avocado Chimichurri

Portobello Steaks with Avocado Chimichurri

Grilled, marinated portobello steaks with a spicy avocado chimichurri sauce! An incredibly hearty and flavorful 30-minute plant-based meal!

PREP TIME 15 minutes
COOK TIME 10 minutes
TOTAL TIME 25 minutes
ServingsCourse Entree
Cuisine Argentinian-Inspired, Gluten-Free, Vegan
Freezer Friendly No
Does it keep? Best when fresh



  • 3-4 large portobello mushrooms (stems removed, wiped clean)
  • 1/3 cup balsamic vinegar
  • 1/4 cup olive oil
  • 1/2 tsp cumin
  • 1/2 tsp black pepper
  • 1/4 tsp smoked paprika
  • 3 cloves garlic (minced)
  • 1 Tbsp steak sauce (optional // vegan friendly, like A1)


  • 1 1/2 cups parsley (finely chopped // either kind will work, but flat leaf Italian parsley is best)
  • 3 cloves garlic (minced)
  • 1 medium shallot (minced)
  • 1/4 tsp red pepper flake
  • 3-4 Tbsp olive oil (extra virgin when possible)
  • 3 Tbsp lemon juice (for more traditional chimichurri, sub red or white vinegar)
  • 1/2 tsp each sea salt and black pepper
  • 1 small ripe avocado (cubed // a non-traditional addition, but one that adds healthy fats, fiber, and creaminess!)


  • Add portobello mushrooms to a shallow baking dish or large freezer bag. Set aside.
  • In a small mixing bowl, whisk together balsamic vinegar, olive oil, cumin, black pepper, paprika, garlic, and steak sauce (optional). Taste and adjust seasonings as needed.
  • Add sauce to the mushrooms and use a pastry brush to brush on all sides. Marinate on one side for 5 minutes, then the other side for 5 minutes.
  • In the meantime, prepare chimichurri by adding parsley, garlic, shallot, red pepper flake, olive oil, lemon juice, salt, and pepper to a medium mixing bowl and whisking to combine. Taste and adjust flavor as needed, adding more lemon juice for acidity, salt for flavor, or red pepper flake for heat. Add avocado and toss to combine. Set aside.
  • Heat a grill or a large skillet over medium heat. Cook on each side for 2-3 minutes, or until caramelized and deep golden brown. Brush on any remaining marinade while cooking to infuse more flavor.
  • To serve, top portobello steaks with avocado chimichurri. This makes a great standalone meal, but would also pair well with my Pecan Apple Salad, Pear Walnut Salad, or Vegan Mashed Potatoes! They would also pair well with grilled asparagus and/or cooked quinoa, millet, or brown rice. Best when fresh.


*3 cloves of garlic yield ~1 1/2 Tbsp minced garlic.
*Chimichurri sauce loosely adapted from Bon Appetit.
*Mushroom marinade adapted from my Portobello Mushroom Burgers in our 31 Meals eCookbook!
*For added protein, top with toasted pumpkin seeds or serve with cooked millet, quinoa, or brown rice!
*Nutrition information is a rough estimate calculated with 4 portobello mushrooms, all the olive oil, and without optional steak sauce.

Nutrition (1 of 4 servings)

Serving: 1 portobello steaks with sauce Calories: 354 Carbohydrates: 14.4 g Protein: 3.7 g Fat: 32.8 g Saturated Fat: 4.5 g Trans Fat: 0 g Cholesterol: 0 mg Sodium: 322 mg Potassium: 673 mgFiber: 4.4 g Sugar: 6.3 g Vitamin A: 1950 IU Vitamin C: 54.5 mg Calcium: 60 mg Iron: 2.3 mg