1/4 cup plus 2 tablespoons lightly packed, fresh sage leaves, washed and patted dry
2 tablespoons lightly packed, fresh flat-leaf parsley leaves, washed and patted dry
1 clove garlic, peeled
1/4 cup plus 2 tablespoons pine nuts or walnuts
1/2 cup olive oil, divided
3 tablespoons freshly grated Parmesan or Pecorino Romano
1/2 teaspoon coarse salt (kosher or sea salt), plus more to taste
1 1/2 pounds ground chicken
1/3 cup dried breadcrumbs
1/3 cup milk
4 onion rolls or hamburger buns, split
2 tablespoons reduced-fat mayonnaise
In a food processor fitted with its metal blade, chop the herbs, garlic and pine nuts. With machine running, drizzle through its feed tube 1/4 cup, plus 2 tablespoons, of the olive oil in a thin, steady stream. Add the cheese and salt to taste; process briefly to a nearly smooth consistency. Let sit at room temperature.
Preheat or prepare a grill for medium heat.
In a large bowl, combine the chicken, breadcrumbs, milk and 1/2 teaspoon salt. Gently form mixture into 4 patties about 1/2 to 3/4 inch thick. Patties should hold together firmly, but don't compact them. Rub each side of patties lightly with remaining oil.
Grill burgers uncovered for 12 to 14 minutes total or until brown, crisp and fully cooked. Grill each side twice, rotating burgers to get crisscross grill marks. To serve, spread the mayonnaise on bottoms of the rolls, place a burger on each, generously spoon on pesto and replace roll tops.
Makes 4 large burgers.