Preheat the oven to 400°F.
In a food processor, process the garlic, olives, capers, artichoke hearts and olive oil to a coarse paste.
Toast the bread on the oven rack for 6 minutes, or until crisp and browned. Spread the olive paste thickly over the toasts and serve.
Do ahead: The olive paste can be refrigerated for 2 days. Let it return to room temperature before using.Adapted from Mario Batali