Savory Roasted Flat Mushrooms with Green Onion, Thyme & Butter

Roasted Flat Mushrooms with Green Onion, Thyme & Butter
Roasted Flat Mushrooms with Green Onion, Thyme & Butter is a delicious and easy-to-make dish. Perfect as a side or even as a main highlight on your table, these mushrooms are packed with flavor. The mix of buttery goodness and fresh herbs creates a warm and inviting dish that will impress your family and friends.
Why Make This Recipe
This recipe is simple yet incredibly flavorful. Roasting flat mushrooms brings out their natural umami taste, while the green onions and thyme add fresh and aromatic notes. The butter not only enhances the taste but also gives the mushrooms a luscious texture. This dish can be prepared in under an hour and makes for a delightful addition to dinner parties or cozy weeknight meals. Best of all, it uses straightforward ingredients that are easy to find!
How to Make Roasted Flat Mushrooms with Green Onion, Thyme & Butter
Ingredients:
- 8 large mushrooms (flat, portobello, "BBQ," around 10-12cm / 4-4.5" wide, stem tips trimmed)
- 100g / 7 tbsp unsalted butter (softened)
- 1 cup green onion (thinly sliced)
- 1/3 cup parsley (finely chopped)
- 1 tbsp fresh thyme leaves (or 1 tsp dried)
- 1/2 tsp salt
- 1/4 tsp black pepper
- 3 tbsp chopped scallions
- 1 dozen thyme stalks
Directions:
- Clean mushrooms: Start by cleaning the mushrooms gently to remove any dirt. For more guidance, check Note 1.
- Preheat oven: Set your oven to 200°C / 390°F (180°C fan).
- Mix butter: In a medium bowl, combine the softened butter with the green onion, parsley, thyme, salt, and pepper until well blended.
- Smear mushrooms: Place the mushrooms gill side up on a large baking tray. Spread the butter mixture evenly over the surfaces of the mushrooms. Cover with foil to keep the herbs vibrant.
- Bake: Bake in the preheated oven for about 25 minutes until the mushrooms are tender.
- Serve: Once cooked, arrange the mushrooms on a platter along with the melted butter and juices from the tray. Top with extra scallions and thyme stalks for garnish. Serve warm.
How to Serve Roasted Flat Mushrooms
These roasted flat mushrooms can be served as a side dish alongside grilled meats, or as a tasty appetizer. You can also enjoy them over a bed of rice or alongside a simple salad. The buttery sauce is perfect for drizzling over your favorite bread!
How to Store Roasted Flat Mushrooms
If you have any leftovers, store them in an airtight container in the refrigerator. They will stay fresh for about 2-3 days. When ready to eat again, simply reheat them in the oven or on a skillet until heated through.
Tips to Make Roasted Flat Mushrooms
- Make sure to use fresh herbs for the best flavor.
- Feel free to adjust the seasoning according to your taste.
- For added depth, you can sprinkle some grated cheese over the mushrooms halfway through baking.
Variation
You can try adding different herbs like basil or oregano to the butter mixture for a different flavor profile. If you want some heat, consider adding a pinch of red pepper flakes.
FAQs
-
Can I use other types of mushrooms?
Yes, you can use other large mushrooms like shiitake or cremini, but cooking times may vary. -
Is this recipe suitable for vegetarians?
Absolutely! The recipe is entirely vegetarian as it uses butter and vegetables. -
Can I prepare this ahead of time?
Yes, you can prepare the butter mixture and smear it on the mushrooms ahead of time. Just cover them and refrigerate until you’re ready to bake.
Enjoy making and tasting these Roasted Flat Mushrooms with Green Onion, Thyme & Butter – a delightful treat for all!

Roasted Flat Mushrooms with Green Onion, Thyme & Butter
Ingredients
Mushroom Preparation
- 8 large large flat mushrooms (portobello, around 10-12cm / 4-4.5" wide, stem tips trimmed) Use flat mushrooms for best results
Butter Mixture
- 100 g unsalted butter (softened) Ensure the butter is softened for easy mixing
- 1 cup green onion (thinly sliced)
- 1/3 cup parsley (finely chopped)
- 1 tbsp fresh thyme leaves (or 1 tsp dried) Use fresh herbs for better flavor
- 1/2 tsp salt
- 1/4 tsp black pepper
- 3 tbsp chopped scallions For garnish
- 1 dozen thyme stalks For garnish
Instructions
Preparation
- Clean the mushrooms gently to remove any dirt.
- Preheat your oven to 200°C / 390°F (180°C fan).
Mixing
- In a medium bowl, combine the softened butter with the green onion, parsley, thyme, salt, and pepper until well blended.
Baking
- Place the mushrooms gill side up on a large baking tray and spread the butter mixture evenly over the surfaces.
- Cover with foil to keep the herbs vibrant.
- Bake in the preheated oven for about 25 minutes until the mushrooms are tender.
Serving
- Once cooked, arrange the mushrooms on a platter along with the melted butter and juices from the tray.
- Top with extra scallions and thyme stalks for garnish. Serve warm.