Cook onion in 3 tablespoons oil in a 10-inch heavy skillet over moderate heat, stirring occasionally, 4 minutes. Reduce heat to low and cook, covered, stirring occasionally, until onion is golden and soft, 8 to 10 minutes more. Add tomatoes, paprika, sugar, and salt and cook, uncovered, over moderately low heat, stirring frequently, until mixture is very thick (jam-like), 25 to 30 minutes. Puree in a blender or food processor, then transfer to a bowl to cool.
Preheat oven to 350 degrees F.
Brush both sides of bread slices with remaining 3 tablespoons oil, then arrange in 1 layer on a baking sheet and bake, turning once, until lightly toasted, about 15 minutes total.
Spread the toasts with the confit, top with a chive baton, and place an olive 1/2, rounded-side up, in the center of each.
Cooks' note: Confit can be made 4 days ahead and chilled, covered. Bring to room temperature before using.
Recipe courtesy of Gourmet Magazine