Combine all of the rub ingredients together and grind using a spice grinder, small food processor, or mortar and pestle.

For each duck breast, score a diamond-pattern grid through the fat and skin, being careful not to cut into the meat. (This helps the fat render, as well as allowing the spice rub to penetrate the surface more easily). Rub the spice mixture into the duck breasts on both sides. Allow the duck to rest, ideally overnight, but at least an hour or two.

Heat a pan over medium high heat and coat the bottom with olive oil. When hot, add the duck breasts, fat side down and turn the heat down to medium. Let the fat render from the duck breasts and slowly brown the skin. This process should take about ten minutes. Turn the duck breasts over. Cook for 2–3 minutes on this side if they are small, or for 4–6 minutes if they are large. Cover loosely and let rest off the heat for five minutes before slicing for medium rare. Slice thinly and fan out to serve.