Whisk together the chicken broth, soy sauce, 1 tablespoon cornstarch, 3/4 teaspoon ground ginger, and brown sugar in a bowl.
Combine 1/4 cup cornstarch, 1 1/2 teaspoons ground ginger, and curry powder in a large, sealable plastic bag and shake to mix. Add the chicken to the bag and toss until well coated.
Heat the olive oil and sesame oil in a wok or large skillet over high heat. Cook and stir the chicken in the hot oil until golden brown, 3 to 5 minutes. Add the green onions and bell pepper to the pan, cooking another 2 to 3 minutes. Stir the sauce mixture into the chicken and vegetable mixture; reduce heat to medium. Sprinkle sesame seeds over the dish and bring to a boil; allow to boil until the sauce thickens, 3 to 5 minutes. Remove from heat; add cashews and toss to serve.