If using flank steak, follow same instructions as steak strips.
If using chicken breasts, pat dry and cut into 1" dice. Season all over with a pinch of salt and pepper. Follow same instructions as steak strips in Step 4, stirring occasionally over medium heat with cremini mushrooms until chicken reaches minimum internal temperature, 5-7 minutes.
If using NY strip steak, pat dry and season both sides with a pinch of salt and pepper. Cook separately from mushrooms, in a medium non-stick pan over medium heat with 2 tsp. olive oil. Cook until browned and steak reaches a minimum internal temperature of 145 degrees, 9-11 minutes per side. Slice steak into 1/4" slices, and place on risotto with mushrooms.