Bring medium saucepan of water to a boil over high heat. Cut an "X" into bottoms of tomatoes with small knife. Add tomatoes to boiling water and cook until skin is loosened, about 1 minute. Drain tomatoes; cool slightly and peel off skins.
Combine tomatoes, Knorr® Chicken flavor Bouillon Cube, onion and peppers in blender or food processor and process until almost smooth.
Heat oil in large nonstick skillet over medium-high heat and cook tomato mixture until it comes to a boil. Reduce heat to simmer and cook, stirring occasionally, 5 minutes for flavors to develop. Serve topped with sliced green onions.