Whisk together the lemon juice, olive oil, salt, pepper, and thyme. Pour over the chicken breasts in a nonreactive bowl. Cover and marinate in the refrigerator for 6 hours or overnight.
Heat a charcoal grill and cook the chicken breasts for 10 minutes on each side, until just cooked through. Cool slightly and cut diagonally in ½-inch-thick slices.
Skewer with wooden sticks.