Mix the cornstarch, brown sugar, chicken broth, and soy sauce in a bowl until smooth.

In a nonstick pan, heat 1 tablespoon of oil over medium-high heat; stir-fry the chicken until no longer pink. Remove from the pan and set aside.

In the same pan, heat remaining oil over medium-high heat; stir-fry mushrooms, water chestnuts and ginger, about 3-5 minutes. Add in snow peas and saute 1 minute more.

Stir in broth mixture and green onions; bring to a boil. Cook and stir until sauce is thickened, 1-2 minutes.

Stir in chicken and cashews and cook another 1 - 2 minutes. Serve over rice.