Heat a large frying pan on a very high heat.

Trim mushrooms stalks and add to the pan with a little olive oil. Sear mushrooms for about 4 minutes on each side, turning every 2 minutes (about 8 mins all up).

Meanwhile, finely chop garlic and remove leaves of thyme from the stalks and stir both (if using) into the mayo.

Serve mushies with a good dose of salt & pepper with mayo and leaves on the side.