In a large skillet, combine the champagne, sugar, water, vanilla bean and cardamom pods. Bring to a boil over medium high heat, stirring to dissolve sugar. Reduce heat. Add pears, cover and simmer 8-10 minutes until pears are just tender. remove from heat. Drain pears, discard liquid and spices. transfer to a bowl, cover and chill for at least an hour.
Preheat oven to 325 degrees. Place pistachios, orange zest, salt, cinnamon, and sugar in a food processor. Pulse until nuts are ground. Add the melted butter and pulse 2-3 times just until combined. press mixture into the bottom of a 9" spring form pan. Bake for 10-12 minutes just until it starts to brown. Remove from oven and set aside to cool.
in a large mixing bowl combine the cream cheese, Sour cream, sugar, vanilla and cardamom. Cream ingredients together until well combined. Add the egg and flour. Mix just until evenly distributed. Don't over mix. por cream cheese mixture into the spring form pan with the prepared crust. Bake for 60 minutes. ( I recommend using the water bath method.) Leave the cheesecake in the oven, but turn the oven off and crack open the door. allow oven to cool completely. remove the cake from the oven, cover with plastic wrap and refrigerate for at least 1 hour.
Just before serving, slice the pears lengthwise into 1/4 - 3/8" wide slices. Arrange the pears in a circular fan design on top of the cake.