You can assume that a recipe that calls for cubed chicken requires boneless, skinless chicken breast because the bones in wings and thighs restrict you from.
Lots of chicken dishes, from stir-fries to salads, call for diced breast meat. An even dice ensures uniform cooking and shows off your knife skills too. Plus, cutting.
Work with one half a chicken breast at a time, cutting the solid breast on the bias into 3 or 4 smaller slices or Cube or dice each piece, one at a time only.