Making Vegetable Stuffed Portobello Mushrooms is a great starter or breakfast idea. Mushrooms may not be for everyone, but we certainly love them in all shapes and varieties. They add a depth of flavour to vegetable dishes like no other ingredient.
These vegetable stuffed portobello mushrooms can be served as a starter or side. Their perfect for breakfast lunch or dinner, making them incredibly versatile.
I love making these as a starter when entertaining as you can prep them and just turn the oven on when your guests arrive so that they are ready once drinks have been served and the conversation has warmed up. They do look impressive and work well on a rainy summers day or during colder months.

You can stuff portobello mushrooms with almost any vegetable so if you don’t have the ingredients we’re suggesting in the recipe you can substitute for ingredients with a similar texture or flavour without much hassle. Just be sure to keep the cooked volume of ingredients the same. Spinach works really well as a complementary flavour for mushroom so does tomato, courgette, peppers and onion.
Garlic is an absolute must when it comes to flavouring the mushrooms so I’d recommend always using fresh garlic or adding garlic granules if you’re out of fresh cloves.
Adding Creaminess with a Sauce

Mushroom like creaminess, and in most circumstances adding a bit of cheese or a cream sauce to the filling would suffice. But as we’re opting for a vegetarian and vegan variation it’s best to make a creamy vegan white sauce using plant-based milk such as soy. If you’re not concerned about using dairy-based milk and butter then you can use them of course. But adding a cream sauce is a must as it will help to add richness to the mushrooms while keeping it animal product free. And as always choose high welfare and organic ingredients if you can.


Vegetable Stuffed Portobello Mushrooms
Ingredients
- 4 large organic portobello mushrooms
- 4 cloves organic crushed garlic
- 1 tbsp extra virgin, organic olive oil with a bit extra for brushing the mushrooms
- 1 small organic onion, finely chopped
- 200 g organic spinach roughly chopped
- 4-5 organic cherry tomatoes chopped
- 1 handful finely chopped organic basil
- 1-2 tbsp golden breadcrumbs
For the Sauce
- 1 tbsp extra virgin olive oil
- 2 tbsp all-purpose organic flour
- 2/4 cup soy milk or other plant based milk
- 1 pinch nutmeg
Instructions
- Pre-heat the oven to 400F/200C/180C fan assisted / gas mark 6
- Remove the stalks from the mushrooms, brush them with a little bit of olive oil, salt & pepper and place the mushrooms, stalk side down, on a baking tray in the oven. Bake the mushrooms for 10 minutes until the water starts to drip out. Finely chop the stalks and set aside for later.
Make the Vegetable Filling
- While the mushrooms are baking in the oven, prepare the stuffing by heating the olive oil in a medium-sized pan. On medium heat fry the onion, tomato, mushroom stalks and garlic until they soften. Once the onion has become translucent add the spinach and simmer until all the water evaporates completely then stir in the basil and remove from the pan and set aside. Season to taste.
Make the Creamy Sauce
- In the same pan as making the filling add a tablespoon of olive oil and warm over medium heat. Then lower the heat, add the flour and combine, be careful not to burn the mixture. Once the flour and oil have created a thick mixture slowly add the milk and stir vigorously using a whisk. Let the sauce simmer until it becomes nice and thick, almost pasty.
Put it All Together
- Stuff the mushrooms with equal amounts of the filling. Then top with the creamy sauce and lastly sprinkle with the breadcrumbs.
- Bake in the oven for a further 15 minutes or until it becomes slightly golden.
Further Ideas for Recipe Variations
You can combine the creamy sauce with the vegetables before filling the mushrooms. This will create an overall creaminess and not just for the top bit. Vegetables can be swapped out as mentioned above, perhaps using chard or finely chopped broccoli instead of the spinach.
If you do have a good quality melting vegan cheese, you can replace the creamy sauce with a sprinkle of cheese. For vegetarians who aren’t concerned with using cheese, butter or milk you can replace the vegan ingredients with vegetarian options. A sprinkle of blue cheese added over the top is particularly tasty and complements the mushrooms and spinach exceptionally well. Don’t forget the black pepper for an added kick.