Preheat your oven to 400°F (200°C).
Prepare the mushrooms: Clean the mushrooms gently with a damp cloth and remove the stems if necessary.
Lightly fry the mushrooms: In a frying pan, heat the olive oil over medium heat. Lightly fry the mushrooms, cap-side down, for about 20 seconds to ensure they absorb some flavor.
Arrange the mushrooms: Place the mushrooms, stalk side up, in a shallow roasting tin.
Mix the garlic butter: In a bowl, combine the softened butter, finely chopped garlic, fresh thyme, lemon juice, salt, and pepper until well mixed.
Top the mushrooms: Spoon a little of the garlic butter mixture onto each mushroom, making sure they're generously coated.
Add breadcrumbs: Lightly press fresh breadcrumbs on top of each mushroom for that extra crunch.
Cook: You can either refrigerate them for later use or cook right away. Bake in the preheated oven for 10 minutes until golden and delicious!