Finely grated Parmesan cheese and chopped fresh parsleyfor garnish
Preheat the oven to 350°F.
Heat 2 tablespoons of the oil in a large pan over medium-high heat and add the shallots and mushrooms. Sauté for 10 minutes until they are tender and golden brown, and any liquid that has been released has evaporated. Add the Marsala and thyme, and scrape to release any bits from the bottom of the pan. Add the chicken broth and cream and bring to a simmer until the sauce reduces and forms a bit of a glaze.
While the mushrooms are cooking, brush the baguette slices with the remaining 3 tablespoons olive oil, lightly sprinkle with salt, and place on a baking sheet. Bake for about 4 minutes until very lightly golden and remove from the oven.
Spoon the mushroom mixture over the crostini slices and finish with a sprinkle of Parmesan and parsley.