Heat 1 tablespoon olive oil in a large skillet over medium-high heat for about a minute. Add the chicken and season it with sea salt & pepper. Continue to saute chicken over medium-high heat for 8-9 minutes, stirring occasionally, until browned and cooked through.
Remove chicken to a separate bowl and reduce heat to medium. Add 1 tablespoon olive oil, sesame oil (if using), onion, and minced garlic to the pan. Cook for one minute, then stir in the mushrooms. Continue sauteing over medium heat for five minutes or until they soften and brown, stirring occasionally.
Stir in the kale. Season with crushed red pepper, ginger, and soy sauce, and continue to saute over medium heat, stirring frequently, until kale is just wilted. Stir chicken back in until heated through.
Serve over cooked rice (or over cauliflower rice, if low carb).
Notes
I used 1.5 lbs chicken because that was the size of my clearance package today, but next time I would probably just use one pound for a better chicken-to-veggie ratio since the kale cooks down so much.