Mushies!

Gently wipe the mushrooms clean with damp cloth or paper towel and roughly slice. Return the pan to a medium-high heat with another drizzle of oil and a knob of butter. When hot, fry the mushrooms for 3-5 minutes until soft and golden, shifting as they colour. You may need to do this step in batches, adding more oil and butter between batches. Season to taste, remove from the pan, and add to the bowl of stroganoff.