Bring 2 qt. water to a boil in 3-qt. saucepan. Add plantains and boil until tender, about 25 minutes.

Meanwhile, season chicken, if desired. Heat 1 Tbsp. oil in large nonstick skillet over medium-high heat and brown chicken, turning once, about 3 minutes; remove and set aside.

Cook onion and green pepper in same skillet, stirring occasionally, until tender, about 4 minutes. Stir in tomato and 2 cloves garlic and cook, stirring, 30 seconds. Add chicken, 1 cup water and 2 tsp. Knorr® Chicken flavor Bouillon. Bring to a boil, reduce heat and simmer covered, until chicken is thoroughly cooked, about 15 minutes. Remove chicken and shred; return to skillet.

Drain and mash plantains; reserving 1/2 cup cooking liquid. Heat remaining 1 Tbsp. oil in same saucepan over medium heat, and cook remaining garlic, stirring, 30 seconds. Add plantains and remaining 1 tsp. Bouillon. Cook, stirring, until flavors to develop, about 2 minutes. Stir in reserved cooking liquid, as needed, to loosen plantain mixture.

Spray ½ cup dry measuring cup with no-stick cooking spray and spoon plantain mixture into cup. Invert onto serving plate. Repeat with remaining plantains. Spoon chicken stew over plantains. Serve, if desired, with a salad.