Combine sour cream, mayo, 1/2 cup parsley, chives, lemon juice, salt, and garlic. Mix well. Allow dip mixture to chill thouroughly.
Trim and hollow out cabbage into form of bowl. Spoon chilled dip into cavity of cabbage and sprinkle top of dip with chopped parsley. Serve dip with snow peas, green onion fans, blanched asparagus, broccoli, or carrots.