In a medium bow, combine garlic, vinegar, sugar and salt until dissolved. Add carrots and radishes, tossing to combine. Set aside to marinate.

Season chicken lightly with salt. Warm nonstick grill pan over med. heat. Grill chicken until cooked though, about 6-7-mins per side. Transfer chicken to a cutting board, tent with foil and let rest.

Tear bough centers out of bottom of baguette. Lightly toast baguettes in toaster oven. (I would just use the hot grill pan).

Thinly slice chicken. Spread 1 tbsp of mayo on 1 bottom piece of baguette. Top with 1/4 of cucumber slices and 1/4 chicken slices. Top with 1/4 carrot mixture and a few cilantro leaves. Cover with top half of baguette. Repeat with remaining baguette pieces and filling.