Cover the bottom of a baking sheet with aluminum foil. Rinse the pears, pat dry and put on a baking sheet. Cover with additional foil and roast the pears for 1 hour. Peel the pears and cut them in half.
On a cutting board, cut out 12 circles from the pear halves, using a 1/2-inch circle cutter. Avoid the seeds. Shave off excess pear to make sure all of the circles are the same height. I suggest you make them a 1/2-inch high.
Put the pear circles into large serving spoons. Pour some Champagne over the pears and sprinkle with cinnamon. Arrange some diced cucumber on top of each pear circle and serve.