In a saucepan, over high heat, melt the half butter and add the onions, garlic, thyme, sage and mushrooms and cook for 5-8 minutes until coloured.
Keep some mushroom on the side for garnish.
Add the wine to the pan and allow to evaporate for 2 minutes.
Add the chicken stock and cream and bring to the boil. Reduce the heat and simmer for 5-8 minutes without lid until the vegetables are fully cooked.
Remove from the heat and blend using a hand blender until very smooth, adding the rest of the butter.
Check the seasoning.
Serve and garnish with toasted bread.