Preheat oven to 425 degrees (f). Spread the blue cheese on the pizza crusts. Core the pears and cut them lengthwise into thin slices. Arrange the slices of pear on top of the cheese. Drizzle with the honey and sprinkle 1/2 teaspoon of thyme over each pizza. Bake the tarts on the bottom rack of the oven for about 8 minutes, until heated through. Then place under the broiler for 1 to 2 minutes longer to brown the pears lightly. Cut each tart into 8 wedges and serve warm. Makes 4-5 servings.