Put a large heavy frying pan, big enough to hold all the mushrooms in one layer, over heat and add a couple of glugs of extra virgin olive oil. Depending on the size of your mushrooms, leave any small ones whole but tear, break or slice the larger ones up. Add them all to the pan and give it a shake to toss the mushrooms in the oil.
Add the chopped garlic and fresh herbs and shake the pan again. Add a pinch of salt and pepper and the crumbled chili and leave to fry gently for a few minutes. If the mixture becomes dry, pour in a little more oil.
Once the mushrooms have got some color going on, after about 3-4 minutes, add the butter and a squeeze of lemon juice to give a nice twang -- don't go overboard here, you don't need much -- and toss again.