Cilantro-Stuffed Chicken Breasts with Poblano Chile Sauce

Preheat broiler and lightly brush a shallow baking pan with some oil. Finely chop garlic and in a small bowl stir together with cilantro and salt. Pat chicken dry and trim any fat. To form a pocket in chicken for cilantro filling: Put a chicken breast half on a cutting board and, beginning in middle of 1 side of breast half, horizontally insert a sharp thin knife three fourths of the way through center, moving knife in a fanning motion to create a pocket. (Opening will only be about 1 inch wide.) Make pockets in remaining chicken breast halves in same manner. Put about 1/2 tablespoon filling into each pocket and with finger spread evenly. Transfer chicken to baking pan and brush with remaining oil. Season chicken with salt and pepper and broil 5 to 6 inches from heat 7 minutes. Turn chicken over and broil until just cooked through, 3 to 5 minutes more. Serve chicken with sauce.