In a colander
rinse olives under cold water 1 minute and in a large bowl cover with cold water. Soak olives
4 hours to remove excess salt and drain
To make the harissa: In a mortar with a pestle, an electric spice grinder, or a cleaned coffee grinder, grind seeds fine. If using mortar and pestle
, add chiles, garlic, and salt and pound, to taste. If using a spice or coffee grinder
, transfer seeds to a small food processor
and add chiles, garlic, and salt. Grind mixture to a paste. Add pepper and oil and pound or puree to a coarse paste.
In a large bowl stir together the harissa
and olives and marinate, covered and chilled, at least 6 hours or overnight. Olives may be prepared 1 week ahead and kept chilled, covered.
Serve olives at room temperature.