The versatility of chicken breasts allows for myriad preparations, a wide variety of seasoning choices and several cooking options. A slow cooker envelops chicken breasts in gentle, moist heat, and the redistribution of the cooking liquid after it condenses on the underside of the lid keeps them in a moist environment -- ideal for lean proteins. Although cooking times vary among slow cookers, allow approximately five hours of cooking time when preparing two chicken breasts.
Crush two garlic cloves with the broad side of a chef's knife and set aside. Cut one medium onion into 1/2-inch slices and set aside.
Heat 2 tbsp olive oil in a sauté pan over medium-high heat. Season the chicken breasts to taste with kosher salt and freshly ground black pepper and place them skin-side down in the sauté pan.
Sear the chicken on each side for two minutes. Searing the chicken breasts produces a golden-brown, caramelised colour unattainable in a slow cooker.
Place the onions, garlic and 2 cups chicken stock in the slow cooker. Place the chicken breasts on top of the vegetables. Placing the chicken on the vegetables allows steam to circulate underneath, which promotes even cooking.
Secure the lid and cook on low for five hours or until they have an internal temperature of 73.9 degrees Celsius.