Place garlic, cilantro, lemon juice, sugar and salt in the blender. With motor running add oil in a stream until a soft dressing is obtained.
Place hearts of palm, avocados and tomatoes in a bowl and combine.
Toss genly with onion and vinaigrette.
Line 8 salad plates with lettuce and mound avocado and hearts of palm mixture on top.Force hard boiled eggs through a strainer and sprinkle over salad.