Stuffed Portobello Mushrooms with Spinach and Feta

These easy stuffed portobello mushrooms with spinach, feta and sautéed garlic are marinated in balsamic vinegar and make an absolutely perfect veggie side dish, or even first course! With only a few main ingredients, you’ll find these mushrooms don’t require any other bells and whistles to be fabulous, flavorful show stoppers. 

They’re vegetarian, gluten-free, keto and packed with leafy green vitamins and minerals!

It’s March and spring is right around the corner – with all my spring clothes from last year that I hope to fit into after a very buttery, breaded, pumpkin spice snickerdoodley Fall and Winter. Time to slim down in the healthiest way I know how – with all those wonderful leafy green nutrients… and a little bit of feta.

I love serving stuffed portobello mushrooms as a first course at a dinner party. They can easily be made ahead of time, they look so enticing and also make a perfect complement to an entree like roasted duck or beef bourguignon! 

A Few Common Questions:

1. Can you eat the gills of a portobello mushrooms?

Yes. They’re definitely edible, as well as the stems, but the stems have a thicker, more fibrous texture and you’ll want to carefully remove as much of them as you can to make room for the spinach and feta in this recipe. You can also remove the gills if you want to make even more room, but it’s not entirely necessary.

2. What’s the difference between “portobello” and “portobella” mushrooms?

Portobello mushrooms are also referred to as “portobella” mushrooms, and both are correct terms for the same kind of mushroom. It’s only a matter of size. When the crimini mushroom is small, it’s referred to as a “portobella” or “baby bella” mushroom, and when they get bigger, they’re branded as “portobello” mushrooms. It’s as simple as that.

3. Can I use frozen spinach for this recipe?

Yes you can, although fresh, sautéed spinach has more flavor pizzaz and a brighter green color that just makes for a prettier stuffed mushroom. However, it’s a misconception that frozen spinach is less nutritious.

Spinach is frozen at peak freshness and it’s nutrition doesn’t diminish, whereas fresh spinach will lose nutritional value while it wilts. So ideally, go for the very freshest spinach, but if you can’t find it, frozen will be just as healthy (just a little less green).

If you use frozen spinach, make sure to thaw and squeeze out as much water as you can. Brown your minced garlic then sauté thawed spinach in the olive oil and garlic for 4-5 minutes.

4. Can stuffed portobello mushrooms be reheated?

They certainly can! They won’t dry out and the feta won’t melt or become burnt. Simply reheat mushrooms at 350 F. for 10-15 minutes. Stuffed mushrooms will stay perfectly tasty for 2-3 days if stored in a container with a tight lid and refrigerated.

5. What do I need to make this recipe?

• Sharp knife and cutting board
• Frying pan
• Wooden spoon or spatula
• Medium-size mixing bowl
• Glass pyrex or foil-lined baking sheet

How to Make Stuffed Portobello Mushrooms with Spinach and Feta – Step by Step

1. Preheat oven to 400 F. Remove as much of the portobello stems from 2 portobello caps as you can without damaging the caps. You don’t have to remove the mushroom gills. In a medium-size mixing bowl, pour ¼ cup olive oil and 1 tbsp. balsamic vinegar, and sprinkle with garlic powder and sage spice. Gently coat the mushrooms in the mixture and set aside to marinate.

2. Mince 4 garlic cloves and set aside.

3. Remove the stems from 3 cups of fresh spinach and coarsely chop. Set aside.

4. Add 3 tbsp. olive oil to a frying pan and brown minced garlic for 3-4 minutes.

5. Place chopped spinach right on top of the garlic and allow it to wilt down and sauté for 4-5 minutes. As it wilts, gently stir into the garlic and oil. Sprinkle with salt and pepper and set aside when done.

6. Place mushroom caps face down in a pyrex or baking sheet and bake for 10 minutes.

7. Remove pyrex and pour out any liquid if any released. Gently turn caps over and stuff with spinach. 

8. Sprinkle about 3 tbsp. of crumbled feta cheese (1½ tbsp. each) on top of the spinach. Bake for 20 minutes more and serve.

Now that’s a stuffed portobello mushroom! Aren’t they gorgeous? And again, to make ahead of time and reheat, simply bake for 10-15 minutes at 350 F.

And for more veggie side dish inspiration, help yourself to these recipes!

• Sautéed Swiss Chard with Caramelized Shallots
• Creamy Curry Cauliflower Soup
• Baked Mashed Potatoes with Roasted Garlic and Herbed Goat Cheese
• Crispy Roasted Cauliflower with Cheddar & Parmesan
• Blistered Shishito Peppers with Soy Sauce, Sesame & Lime

And for more even MORE inspiration, follow me on INSTAGRAM @shekeepsalovelyhome, on PINTEREST and FACEBOOK! And if you ever make any of my tasty drinks or treats, take a picture and tag me. I want to see!