Place dried mushrooms in medium bowl. Add hot water and let soak until softened, about 30 minutes. Remove mushrooms from water, squeezing the excess water back into bowl. Strain and reserve liquid. Slice mushrooms, discarding stems. Heat oil in heavy large skillet over medium heat. Add bacon and chicken and cook until fat renders, stirring frequently, about 3 minutes. Add dried and fresh mushrooms and rosemary and saute 3 minutes. Pour off half of fat. Add shallots to bacon in skillet and saute 1 minute. Add dried and fresh mushrooms and rosemary and saute 3 minutes. Add stock and mushroom-soaking liquid. Boil until reduced to a glaze, about 10 minutes.

Add half-and-half and simmer until beginning to thicken, about 5 minutes. Remove from heat (can be prepared 3 days ahead, cover and refrigerate.) Add pasta to large pot of boiling salted water. Cook until tender but still firm to bite, stirring occasionally. Meanwhile, rewarm mushroom sauce over medium-low heat. Drain pasta. Add to sauce and stir until coated. Mix in 2/3 cup parmesan. Season with salt and pepper. Transfer to plates. Sprinkle with parsley. Serve immediately with garlic toasts, passing additional parmesan separately (see recipe for garlic toasts).