In a large bowl, mix the sliced chicken with two tablespoons of soy sauce and a dash of salt and pepper. Let marinate for about 15-20 minutes.
Heat the olive oil in a large skillet or wok over medium-high heat. Once hot, add the marinated chicken and stir-fry for about 5-7 minutes until cooked through and golden brown. Remove and set aside.
In the same skillet, add the sesame oil. Sauté the minced garlic and ginger for about 30 seconds until fragrant.
Add in the sliced onions and bell peppers. Stir-fry for about 4-5 minutes until they start to soften.
Return the cooked chicken to the skillet. Add the diced mango, remaining soy sauce, and the chili sauce. Stir everything together and cook for another 2-3 minutes until heated through.
Taste and adjust seasoning with more salt and pepper or chili sauce if desired.
Remove from heat and garnish with fresh cilantro.
Notes
Adjust the chili sauce according to your spice preference.