Roasted Flat Mushrooms with Green Onion, Thyme & Butter

These Roasted Flat Mushrooms with Green Onion, Thyme & Butter are a simple yet stunning side dish that elevates any meal. Large, meaty mushrooms are generously smeared with a vibrant herb butter, roasted to tender perfection while retaining their rich, earthy flavor. The foil cover keeps the mushrooms moist and the herbs beautifully green, creating a dish that’s as gorgeous as it is delicious. Perfect as a vegetarian main, a side dish, or part of a meatless spread, this recipe is effortless and packed with flavor!

Instructions

1. 1

   Preheat oven to 200°C / 390°F (180°C fan-forced).

2. 2

   Clean mushrooms by wiping with a cloth or paper towel to remove dirt. Trim stems to the height of the mushroom edge or snap off if fresh (Note 1).

3. 3

   In a medium bowl, mix softened butter, green onions, parsley, thyme leaves, salt, and pepper until well combined.

4. 4

   Place mushrooms gills side up on a large baking tray. Spread the herb butter mixture evenly over the mushroom surfaces.

5. 5

   Cover the tray with foil to keep mushrooms moist and preserve the green color of the herbs.

6. 6

   Bake for 25-30 minutes, until mushrooms are tender and juicy.

7. 7

   Remove from oven and transfer mushrooms to a serving platter, including all butter and juices from the tray.

8. 8

   Garnish with chopped scallions and thyme stalks for a fresh, vibrant look. Serve immediately.

Recipe Notes

• Mushrooms – Use large flat, portobello, or BBQ mushrooms for best results. Smaller mushrooms can work but increase the quantity to maintain portion size. Clean by wiping with a cloth or paper towel; avoid washing as mushrooms are porous and may become slimy or mushy if waterlogged. For thorough cleaning, use a pastry brush to remove dirt from crevices.

• Mushroom gills – Gills are edible and add flavor, so no need to remove them unless making stuffed mushrooms with extra filling space. If preferred, scoop out gills gently with a spoon.

• Stems – Trim long stems to the mushroom’s edge or snap off if fresh. Fresh mushroom stems break off cleanly, making trimming easy.

• Storage – Store raw mushrooms in a breathable container like a brown paper bag or wrapped in a tea towel to prevent sweating and sliminess. Avoid plastic bags or sealed containers, which reduce shelf life.

• Serving suggestions – Serve as a vegetarian main for 3-4, a side for 6-8, or part of a meatless spread with dishes like roasted vegetables or quinoa salad. The buttery juices pair well with crusty bread for dipping.

• Make ahead – Prepare herb butter up to 3 days in advance and store in the fridge. Mushrooms can be cleaned and trimmed a day ahead, stored in a breathable container. Assemble and bake just before serving for best texture.

• Flavor boost – Add a minced garlic clove to the herb butter for extra depth, or sprinkle with a pinch of smoked paprika before baking for a smoky note.

• Leftovers – Store cooked mushrooms in an airtight container in the fridge for up to 3 days. Reheat gently in the oven at 160°C / 320°F for 10 minutes or in a microwave on low power to avoid drying out.

• Nutrition – Values are per serving, assuming 6 servings. This dish is vegetarian and can be made gluten-free by ensuring all ingredients are certified gluten-free.