In a small bowl, cover dried shiitake mushrooms with hot water. Allow to sit for at least 15 minutes. While those are soaking, clean and chop the baby bella mushrooms. Drain reconstituted mushrooms, saving the soaking water. Finely chop reconstituted mushrooms and set aside. Peel head of garlic and place cloves into food processor. Add heavy cream and process for about 30 seconds. In a medium-sized saucepan, heat 2 tbsp olive oil. Add baby bella and shiitake mushrooms, and saute for 2-3 minutes until they start to soften up. Add the mushroom soaking water and the garlic-cream mixture, and bring to a boil. Lower heat to medium and simmer until mixture reduces and coats the back of a spoon, about 15 minutes. (If you are inpatient, whisk 1 tsp of cornstarch into a tbsp or two of additional heavy cream, add to sauce, and simmer a minute or two until thickened). Season to taste with salt and pepper. Serve sauce over prepared pasta.
http://28cooks.blogspot.com/2008/10/mushroom-and-smoked-garlic-cream-sauce.html