In large deep skillet heat oil over medium-low heat. Add onion and bacon; cook about 6 minutes or until onion is tender and bacon just begins to crisp. Stir in mushrooms and 1/4 teaspoon salt; cook about 5 minutes or until mushrooms are tender, stirring occasionally. Carefully stir in 1/3 cup of the Marsala. Cook and stir about 3 minutes or until liquid is absorbed. Stir in rice. Cook and stir over medium heat for 2 to 3 minutes or until rice begins to brown. Stir in the remaining 1/3 cup Marsala. Cook and stir until liquid is absorbed.
Meanwhile, in a large saucepan bring chicken stock to boiling; reduce heat and simmer. Slowly add 1/2 cup of the hot stock to the rice mixture, stirring constantly. Continue to cook and stir over medium heat until liquid is absorbed. Add another 1/2 cup of the hot stock to the rice mixture, stirring constantly. Continue to cook and stir until the liquid is absorbed. Add the remaining hot stock, 1/2 cup at at time, stirring constantly until the broth has been absorbed. (This should take 25 to 30 minutes total.)
Stir in cheese and butter. Season to taste with pepper. Serve with Parmesan Crisps.
Preheat oven to 375°F. Line baking sheets with parchment paper. In a small bowl combine cheese, thyme, and pepper.
Place 1 heaping tablespoon portions of cheese mixture on prepared baking sheets, about 4 inches apart. Pat into a 5- to 6-inch circle. Bake for 4 to 6 minutes or until bubbly and lightly golden brown. Let stand on baking sheet until completely cooled. Carefully remove crisps from parchment paper. (Store in an airtight container for up to 24 hours or freeze for up to 1 month.)