Slice the baguette on the diagonal into 1/2 inch thick pieces (depending on the size of your baguette, you should end up with 15 to 20 slices.) Pour the olive oil into a small bowl. Using a pastry brush, brush each slice of bread lightly on both sides with the olive oil. Place the slices one layer thick on a baking sheet. Toast in a 325 degree oven for 5-6 minutes. Set aside to cool on cooling racks. Heat the butter or olive oil over medium heat in a large, heavy skillet. Add the shallots and cook, stirring occasionally, until softened (about 2 minutes.) Stir in the mushrooms and thyme, season with salt and pepper. Cook until the liquid from the mushrooms is mostly evaporated and the mixture is starting to brown (about 8-12 minutes minutes.) Add the Marsala wine and cook, stirring frequently, until the liquid is evaporated. (If the liquid doesn’t seem to be evaporating after about 5 minutes, turn the heat up a bit and continue cooking.) Stir in the parsley and the cream. Let the mixture simmer until it thickens. Taste for salt and pepper. Top each crostini with a generous spoonful of the mushrooms. Drizzle each crostini with truffle oil and Asiago shavings. Serve the crostini on a platter sprinkled with leftover parsley.
Makes 15 to 20 crostini