Bring a pot of salted water to a boil and add the barley.
Reduce heat to low, cover, and simmer until tender about 30 minutes; drain, rinse, and set aside.
Heat the griddle or grill pan over medium-high heat and season the chicken fillets with salt and pepper.
Grill the chicken 2 minutes per side for thin fillets, or until cooked through for thicker pieces; transfer to a board and chop, then set aside.
Heat the olive oil in a saucepan over medium heat and sauté the halved cherry tomatoes about 1 minute until they begin to soften.
Add the precooked chickpeas, cooked barley, and fresh sage to the pan and toss for about 5 minutes to combine and warm through.
Stir in the chopped grilled chicken, then add the balsamic vinegar and season with salt and pepper; toss for 1 minute to coat.
Serve the salad warm.