Seed and chop tomato; chop bell pepper. Slice 2 green onions and mushrooms, and mince garlic. Place tomato, bell pepper, green onions, mushrooms, and garlic in a large bowl. Stir in peas and next 3 ingredients. Cover and chill, stirring occasionally, 8 hours.
Drain salad, and spoon onto a lettuce-lined platter. Sprinkle with bacon and 1/3 cup sliced green onions.