Preheat the oven to 400 degrees F. Place the bread on a cookie sheet, brush with olive oil and bake until lightly golden brown.
In a saute pan on medium heat, saute the pears in olive oil for 1 minute just to soften them. Season the pears with salt and pepper. Set aside.
In a small saucepan or skillet on medium-high heat reduce the vinegar and port to 1/4 of its original volume. Pour into a small bowl and let cool. It will thicken as it cools.
Place a piece of prosciutto on the walnut toasts, then a small piece of cheese, top with pear and then drizzle the vinegar-port reduction over the top.