Combine chicken pieces with marinade in a large bowl and mix well. Reserve for about 30 minutes.
Prepare and mix the sauce ingredients in a separate bowl.
Heat up a wok with 3 tablespoons of extra virgin olive oil and stir-fry the cashew nuts on low heat until golden brown. Remove and drain on paper towel.
Remove chicken from marinade and using the same oil in step 3, stir-fry the chicken for 2 to 3 minutes on medium-high heat. Remove chicken, discard juice and set aside. Clean wok with kitchen paper towel.
Heat up the wok with 3 tablespoons of extra virgin olive oil, add garlic and ginger, and stir-fry until lightly golden on low heat.
Add in the celery, carrots and straw mushrooms, stir-fry for 2 minutes on medium to high heat.
Then return chicken and roasted cashew nuts to wok, add in the sauce prepared earlier. Cook for another 2 minutes or until chicken is cooked through. Add salt to taste if required.