2 tablespoons extra-virgin olive oil
1/2 onion, finely chopped
3 garlic cloves, minced
2 pounds skinless, boneless chicken breasts or trimmed thighs, cut into 3/4-inch pieces
1 tablespoon soy sauce, plus more for seasoning
1/4 teaspoon toasted sesame oil
Freshly ground pepper
1 tablespoon plus 1 teaspoon finely grated lemon zest
2 tablespoons fresh lemon juice
1 scallion, thinly sliced
Steamed rice, for serving
In a large skillet, heat the olive oil. Add the onion and cook over moderate heat, stirring, until softened, 4 minutes.
Add the garlic and cook for 1 minute.
Add the chicken and cook over moderately high heat, stirring occasionally, until browned all over, 3 minutes.
Stir in the soy sauce and sesame oil, season with salt and pepper and stir-fry until the chicken is cooked through, 3 minutes longer.
Remove from the heat and stir in the lemon zest and lemon juice.
Season with salt, pepper and soy sauce.
Transfer the chicken to a platter, top with the sliced scallion and serve with rice.