In a food processor, pulse the garlic cloves until finely chopped.
Add olives, tomatoes and capers. Pulse until chopped.
Add olive oil and lemon juice and pulse until mixture is very finely chopped and spreadable, but not totally paste-like. Cover and refrigerate an hour or more to allow flavors to develop.
When ready to serve, brush the slices of bread and place an a baking sheet. Broil on high, or grill, until lightly browned.
Spread each crostini with cheese and top with tapenade. Sprinkle with chives and serve.