3 1/4 cups chicken broth
1 ounce dried porcini mushrooms
6 tablespoons butter
2 cups chopped onions
1 cup chopped celery
2 1/2 teaspoons dried marjoram
1 teaspoon dried thyme
3/4 pound fresh shiitake mushrooms, stems discarded, caps coarsely chopped
3/4 pound crimini mushrooms, caps coarsely chopped
1 1/2 teaspoons salt
8 cups 1/2-inch pieces crustless country-style white bread
1/2 cup finely chopped fresh Italian parsley
2 eggs, beaten to blend
Bring 2 cups chicken broth to boil in small saucepan. Add porcini mushrooms. Cover and remove from heat. Let stand 30 minutes to soften. Using slotted spoon, Finely chop porcini. Reserve 1 1/2 cups mushroom soaking liquid for Gravy Base.
Preheat oven to 400°F. Butter 13x9x2-inch baking dish. Melt 6 tablespoons butter in heavy large pot over medium heat. Add porcini, chopped onions,shallots and celery, marjoram and thyme. Cover and cook 10 minutes, stirring occasionally. Add shiitake, crimini and 1 teaspoon salt. Cover and cook until mushrooms soften, stirring occasionally, about 5 minutes. Increase heat to medium-high. Uncover and cook until almost all liquid evaporates and mushrooms brown lightly, stirring frequently, about 8 minutes.
Transfer mushroom mixture to large bowl. Add bread, chopped fresh parsley, remaining 1 1/4 cups chicken broth and 1/2 teaspoon salt to mushroom mixture and stir to blend. Season with pepper. Mix in eggs. Transfer dressing to prepared dish. Cover with aluminum foil. Bake 20 minutes. Uncover and bake until light brown, about 20 minutes.