For the best texture in this bowl, avoid overcooking the cauliflower rice so it stays a bit firm and does not turn mushy under the sauce. If using frozen cauliflower rice or frozen broccoli, be sure to cook off extra moisture so the sauce stays thick and creamy instead of watery. You can substitute boneless skinless chicken thighs for the breasts if you prefer a richer, higher fat option, and you can swap the cheddar for another good melting cheese such as Monterey Jack, Gouda, or Gruyère. This recipe reheats very well for meal prep; store portions in airtight containers in the refrigerator for up to 4 days and rewarm gently in the microwave or on the stovetop with a splash of cream or broth to loosen the sauce.