Place the kale, chopped, into a sauce pan with 1/4 inch of water. Bring water to boil on medium high heat and cover; braise the greens for two minutes. Lift the lid, turn greens and let steam for 1 more minute. Turn off heat.
In a skillet melt butter over medium heat. Mix in brown sugar, soy sauce, vinegar, pepper and garlic. Bring to a boil and remove from heat. Mix in the cashews and pour sauce on the kale. Serve immediately.