You may use any cut of chicken to make your homemade chicken broth, and thus, soup. I like using a mix of boneless skinless chicken breasts plus chicken thighs for the best flavor. Chicken breasts are lean but prone to drying out, while chicken thighs (dark meat) are more flavorful and less likely to dry out as they contain more fat. You may also use store-bought, low-sodium chicken broth with leftover shredded chicken or rotisserie chicken. Learn more about making homemade chicken stock and poaching chicken: How to Make Chicken Stock and How to Poach Chicken.