Place chopped cashews in a pan over low heat and heat the nuts until they are toasty and fragrant – about 1-2 minutes.
Toss into the pan the olive oil, thin-sliced bell pepper, sliced shitakes, fresh ginger, and onion powder. Cook over medium-high heat until the peppers and mushrooms sweat and tenderize in the pan.
Push the ingredients to the circumference of the pan. Toss the shrimp with the salt and pepper before placing them into the center of the pan.
Cook the shrimp for 1-2 minutes per side – until the shrimp is just pink on both sides.
Push the shrimp to the circumference of the pan with the peppers and mushrooms. Reduce the heat to low and let the butter melt in the center of the pan. Add in the remaining ingredients to toast in the butter for about 30 seconds.
Toss all the ingredients together in the pan so the shrimp and veggies are coated in the buttery, sticky sauce. Cook for an additional 1-2 minutes so the ingredients caramelize slightly in the sauce.