In a medium pot combine 3 1/4 cups of the Moschofilero, 1/2 cup of the sugar, and lemongrass. Bring the mixture to a quick boil. Reduce the heat to low, and let simmer for 10 minutes. Pull the pot off the heat and let the lemongrass steep for another 10 minutes. Strain the liquid into a bowl. Take about 1/2 cup worth out and place in a separate pot over medium heat and reduce to a syrup consistency. Let the syrupy mixture chill and set aside for plating.
Peal the pears, core, and finely dice, setting some aside of garnish. In a pot combine the pears, remaining sugar, remaining Moschofilero, and lemon juice. Simmer until the pears are soft. Transfer the mixture to a blender and puree until smooth.
In a stainless steel bowl, combine the Moschofilero-lemongrass reduction and pear puree in a 60/40 ratio. Slowly add the liquid nitrogen, stirring the ingredients as so the mixture does not clump up. Continue to stir until you have a nice creamy consistency (should only take a minute).
To plate: Add a little of the reserved syrup and left over diced pears to a plate. Place a scoop of the sorbet on top and garnish with shiso leaves. Serve immediately.
NotesThis recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.