In a small bowl, cover the dried mushrooms with the boiling water and let stand until softened, about 20 minutes. Drain the mushrooms, reserving 2 tablespoons of the liquid; be sure it doesn't contain any grit. Press any excess liquid from the mushrooms, coarsely chop them and transfer to a plate.
In a large skillet, melt the butter in the olive oil. Add the shallots and cook over moderate heat, stirring occasionally, until wilted, about 2 minutes. Add the chopped mushrooms and garlic and 2 tablespoons of the Marsala and cook, stirring frequently, until the Marsala is slightly reduced, about 2 minutes. Add the bread crumbs and continue cooking, stirring frequently, until completely blended, about 3 minutes.
Scrape the crumb mixture into a large skillet and stir in the remaining 1/2 tablespoon of Marsala and the thyme. Season with salt and pepper and toast over moderately high heat, stirring, until the crumbs are lightly browned and crisp, about 5 minutes.
Make Ahead: The crumbs can be refrigerated for up to 3 days.
Serve With: Pan-roasted chicken breasts (stuff about 1/2 cup under the skin of each of 6 chicken breasts) or pork chops (press 1/2 cup of the crumbs onto each of 6 pork chops); pasta, such as spaghetti, rigatoni or fusilli (toss the crumbs with the cooked pasta, adding a little pasta cooking water, butter, Marsala and Parmesan cheese).
Notes: Chilean wild mushrooms, or porcini, are available at gourmet food stores or by mail order from Marché aux Delices (888-547-5471).