1 lemon
1/2 cup reduced-sodium chicken broth
3 tablespoons reduced-sodium soy sauce
2 teaspoons cornstarch
1 tablespoon canola oil
1 pound boneless, skinless chicken breasts, trimmed and cut into 1-inch pieces
10 ounces mushrooms, halved or quartered
1 cup diagonally sliced carrots, (1/4 inch thick)
2 cups snow peas, (6 ounces), stems and strings removed
1 bunch scallions, cut into 1-inch pieces, white and green parts divided
1 tablespoon chopped garlic