1/4 cup extra-virgin olive oil, plus more for brushing
3 tablespoons fresh orange juice
1 tablespoon white wine vinegar
Salt and freshly ground pepper
Four 6-ounce boneless chicken breast halves, with skin
Orange sections, for garnish
In a mini food processor, pulse the arugula with the snipped chives, capers, garlic and orange zest until the arugula is finely chopped. Add 1/4 cup of the olive oil, the orange juice and vinegar and pulse to a coarse puree. Transfer the salsa to a bowl and season with salt and pepper.
Light a grill or heat a grill pan. Lightly brush the chicken with olive oil and season with salt and pepper. Grill the chicken over moderate heat, turning occasionally, until browned and cooked through, about 12 minutes. Transfer the chicken to plates and top with the salsa. Garnish with the orange sections and serve.