Toss chicken, flour and garlic in medium bowl; set aside.
Melt margarine in large nonstick skillet over medium-high heat and cook chicken, stirring occasionally, until chicken is thoroughly cooked, about 6 minutes. Remove chicken from skillet.
Stir broccoli into same skillet and cook 1 minute. Stir in hot water and Knorr® Homestyle Stock Chicken until melted. Reduce heat to low and simmer 3 minutes or until crisp-tender. Return chicken to skillet; heat through. Remove skillet from heat, then stir in lemon juice.