Melt butter in a sauce pan over medium heat.
Add garlic and yellow onions when the butter is fully melted. Saute for 30 seconds, or until their aroma is released.
Add 1/2 of the thyme and all the rosemary. Saute for another 1.5 minutes, or until the yellow onions are caramelised.
Wash Shiitake, white Shimeji and button mushrooms under running water. Immediately add them to the pan. Stir for 1 minute, or until slightly softened.
Add salt, pepper, all the thyme and chicken stock. Stir until the seasonings are well distributed. Cover and simmer for 20 minutes. Stir occasionally to evenly distribute the heat.
Taste and adjust as preferred. Switch off the heat.
Carefully blend for 2 minutes, or until fine and thick.
Switch on the heat to medium.
Pour the cooking cream, continously stirring for 1.5 minutes, or until the soup comes to a rolling boil.
Once boiling, let it simmer for 1 minute while stirring occasionally.
Switch off the heat.
Dish out onto the serving plates.
Garnish with a sprinkling of chopped parsley. Serve with slider buns or garlic bread.