There is a reason that cashew chicken is a takeout classic. Tender chicken in a sweet, savory brown sauce gets crunch from cashews and pan seared broccoli florets. Smarts: Toss the chicken in a bit of flour to help get a nice golden brown exterior without extra oil.
Rice - For white rice, rinse until clear. Fill a saucepan or Dutch oven (or rice cooker) with rice, water (use 2:1 ratio for water to rice), and some salt. Cover with lid and bring to a boil. Once water boils, stir, lower heat to a low-medium, and cover. Check white rice after ~20 min; brown at ~45 min. Rice is done when it's absorbed all the water. If it's not done, leave the cover on until all water has been absorbed. Take cover off to release steam and fluff with a wooden spoon after 5 minutes. (Can be done up to 5 days ahead)
Broccoli / Ginger / Garlic / Green onions - Prep as directed. (Can be done up to 5 days ahead)
Make stir-fry sauce - Whisk together stock, soy sauce, cornstarch, ginger, garlic, sugar and red pepper flakes. (Can be done up to 5 days ahead)
Heat a wok or saute pan over medium-high heat. Toss chicken in flour. Add first part of cooking oil to wok. When oil begins to shimmer, add chicken. Saute until golden brown, 3 to 4 minutes, and remove chicken from pan and set aside (don’t worry if it isn’t cooked all the way through yet).
Return wok to heat and add second part of cooking oil. Add white parts of green onions (reserve green parts) and broccoli with a sprinkle of salt. Saute until vegetables are tender but still crunchy, 4 to 5 minutes.
Add chicken back to pan. Push all ingredients to the sides forming a hole in the middle. Give your stir-fry sauce a stir and pour into the hole. Wait for it to bubble and darken before tossing to coat everything in sauce. Add cashews and cook until chicken is cooked through and everything is coated in sauce. Remove from heat and toss with green parts of green onions.
If rice was made ahead, reheat it briefly in the microwave.