Blend the onion, chillies and mushrooms in a blender or food processor until minced.
Melt a knob of butter in a frying pan over a medium heat. Add the minced onion, chillies and mushrooms and cook and stir for 2 to 3 minutes.
Add the cream, plenty of crushed black peppercorns, depending on your heat preference, add salt and leave to simmer for around 5 minutes, stirring occasionally. Serve hot.
Tip
Ingredients quantities are a rough guide depending on individual heat strengths.