01 - In a large skillet, heat olive oil over medium heat. Add onion and garlic, sautéing until softened, about 3-4 minutes.
02 - Season chicken breasts with salt and pepper. Add to skillet and cook 5-7 minutes on each side until golden brown and cooked through. Remove chicken and set aside.
03 - In the same skillet, add rhubarb, brown sugar, chicken broth, and apple cider vinegar. Stir and cook for 10 minutes until the rhubarb breaks down and sauce thickens.
04 - Return chicken to skillet. Spoon rhubarb sauce over chicken and simmer for an additional 5 minutes to meld flavors.
05 - Serve hot, garnished with fresh herbs if desired.