If possible infuse the olive oil with basil a couple of days in advance for maximum flavor. Pour olive oil into an airtight container and add the basil leaves. Store in a cabinet or pantry (dark and cool) until ready to use. At that point, add the kumquat juice and salt. The dressing should be used within a week.
Marinate chicken with 2 tablespoons olive oil, sliced kumquats and a dash of salt for 4 hours.
Season chicken well with fresh ground black pepper and top with sliced kumquats and 1 tablespoon chopped basil; roast for 20 - 25 minutes in a preheated 400º F oven.
While chicken bakes, prepare couscous according to package directions. Once simmering, add 2 tablespoons of chopped basil and mix well.
Place couscous in serving dish and add sliced radishes.
Slice chicken breast and serve over couscous along with the roasted kumquats and additional sprinkling of chopped basil. Drizzle the basil and citrus infused olive oil on top.