Juice of 1 lemon
2 tablespoons soy sauce, plus more as needed
1 teaspoon sugar, or to taste (optional)
1 1⁄2 pounds boneless chicken thighs or breasts, cut in 1-inch pieces
3 tablespoons canola oil, divided
2 carrots, sliced 1⁄8 inch thick
3 bell peppers, mix of red and yellow, in 3⁄4-inch pieces
1 large onion, peeled and cut in 1-inch chunks
1 bunch scallions, trimmed of root ends and chopped
Whisk together the lemon juice and soy sauce. Taste for seasoning, adding more soy sauce if you like. If tart, add the sugar to taste. Pour mixture over the chicken in a bowl. Allow to rest.
Heat a large skillet over high heat. Add 1 tablespoon of the oil. Stir-fry the carrots until crisp-tender. Transfer to a large bowl. Add more oil to skillet, if needed. Repeat, in separate batches, with the peppers, then the onion.
Drain chicken from marinade, reserving marinade. Add 1 tablespoon oil to skillet. Stir-fry chicken, in batches if necessary, until cooked through, for 8 minutes.
Return vegetables to skillet with chicken. Pour in reserved marinade. Heat until marinade boils and cook for 1 minute.
Transfer all to a serving bowl; stir-fry the scallions for 1 minute. Scatter them over chicken and vegetables. Serve with steamed rice and more soy sauce. Makes 4 servings.