Heat 2 tablespoons of butter over medium heat.
Saute the onions for 2 minutes.
Add garlic and saute an additional minute.
Add the mushrooms and saute for 3 minutes.
Make a well in the middle of the vegetables and melt the last 6 tablespoons of butter. Once liquid, add the flour, ¼ cup at a time, mixing well between additions. Cook for 4-5 minutes.
Add in the white wine, milk, stock, bouillon cube, bay leaf, thyme.
Mix together well and let simmer for 15 minutes, stirring occasionally to keep the bottom from burning.
Remove from heat and add in the heavy cream.
Use an immersion blender to blend until all chunks are gone.
Salt and pepper to taste and serve, or set aside to use for another recipe.