In a large 12 to 14-inch saute pan, over medium heat, heat the olive oil until hot but not smoking. Add the onions, pine nuts, currants and chili flakes and saute for 4 to 5 minutes until softened.
Add the eggplant, sugar, cinnamon, and cocoa and continue to cook for 5 more minutes. Add the thyme, tomato sauce, and balsamic vinegar. Bring the mixture to a boil.
Lower the heat and simmer the mixture for 5 minutes. Remove from the heat and allow to cool to room temperature, garnish with mint and chili flakes. Serve the caponata spooned on crostini or in middle of table with crostini on side to allow guests to help themselves.
