Cut chicken breast into bite-sized pieces. Finely chop 1 clove garlic and 1 piece fresh ginger. Separate egg, setting yolk aside for other uses.
Mix chicken with the egg white, garlic, ginger, 1 tablespoon soy sauce, 1 tablespoon teriyaki sauce, 1 teaspoon cornstarch, 1 teaspoon Garam Masala, 0.5 teaspoon Ras El Hanout, 1 pinch ground pepper, and 1 pinch coriander powder. Refrigerate for at least 20 minutes.
Chop onions. Cut carrots, bell pepper, and mushrooms into small pieces. Separate pak choi, chopping white stalks into small pieces and keeping green leaves separate.
Heat oil in a wok or large pan over medium-high heat and sear marinated chicken for 3-4 minutes until golden. Remove and set aside.
Fry onions and pak choi stalks for 1-2 minutes. Add carrots and cook for 3-4 minutes. Add bell pepper and cook for 3-5 minutes. Add mushrooms and cook for 2 minutes.
Add spices, cashew nuts, honey, and sambal oelek; fry for 1 minute. Deglaze pan with water and peanut butter and simmer for 3-5 minutes. Season with salt and pepper to taste.
Stir in seared chicken and simmer for 2-3 minutes until cooked through (internal temperature 74°C / 165°F). Add chopped pak choi green leaves and cook for 1-2 minutes.