Toss the crumbled blue cheese, dried cranberries, and walnuts together in a small bowl. Set aside.
Chop off the top of one pear to remove the stem. Peel and slice it lengthwise into halves. With a small sharp paring knife and a melon baler or small cookie scooper, remove the core and seeds leaving a round well. Remove a bit more from the center so you have a nice hole in each pear half. Trim a small slice away from the bottom rounded side of each pear half so that they will sit upright without wobbling. Place the pear halves in a baking dish core sides up and brush them all over with lemon juice using a pastry brush. Repeat with all the pear halves. Use a 2 to 2 1/2 quart shallow casserole dish so that the pear halves all fit snuggly in the dish.
Stuff each pear hole with some of the cheese mixture, mounding it on top of the holes and packing it slightly.
Combine the apple cider, port, pear liquor and brown sugar in a small bowl. Stir well to dissolve the sugar. Pour the mixture by tablespoons over each pear half letting the excess run over in to the dish.
Bake the pears, basting each half every 10 minutes with the cider mixture, for 30 minutes, or until the pairs are tender. Set aside to cool. Serve warm or at room temperature.