In medium saute pan over medium heat, add olive oil, onion and garlic, cook for 2 minutes, do not let brown. Add cabbage, pepper, salt, and vinegar. Mix thoroughly, and cook for 3 to 5 minutes until cabbage is tender. Remove to abowl and let chill in refrigerator until cool.
In large salad bowl, add Iceberg lettuce and toss with blue cheese dressing.
Strain cabbage mixture of any liquid and lightly mix with Iceberg and blue cheese dressing. Add pepper, to taste.