Core pears from the bottoms, leaving stems intact. Score pears with a paring knife in striped or swirl patterns. Peel the skin away in between the score marks. Brush the exposed flesh with lemon juice to prevent browning.
In a 4-quart pot combine the wine, sugar, lemon zest and juice, water, mint, and vanilla bean paste. Cook and stir over medium heat until just boiling, stirring to dissolve the sugar. Add pears and reduce heat to medium-low. Cover and simmer for 10 to 15 minutes or until pears are just tender. Remove and keep warm. Discard liquid.
For sauce, in a medium saucepan heat the ice cream over low heat just until melted. Whisk in the cornstarch. Increase heat to medium. Cook and stir until thickened and bubbly. Cook and stir 2 minutes more. Spoon into dessert dishes and top with pears.