Packaged chicken sausage may be grilled, baked or cooked on the stovetop. Though it is already pre-cooked, it should be heated to at least 165°F regardless of cooking method. Grill: Simply place on the grill or grill pan, turning half way through cooking. Skillet: Add a tablespoon of olive oil to a hot skillet and cook chicken sausage, whole or sliced until golden brown. Oven: Place chicken sausage on a foil-lined baking pan and roast at 400°F until heated through. Microwave: Place chicken sausage on a plate and microwave for 30-40 seconds or until heated through.