Preheat oven to 350°F (180°C)
In an ovenproof dish, roast shallots, garlic, oil, and balsamic vinegar for 30 minutes or until browned. Cool.
In the bowl of a food processor, pulse roasted garlic and shallots and any remaining liquid together until smooth. Add sour cream, mayonnaise, Dijon mustard, lemon juice and grated Parmesan cheese. Process until smooth.
Serve dip with your choice of raw or blanched vegetables, such as carrot and celery sticks, blanched asparagus, grape tomatoes, mushrooms and broccoli or cauliflower florets.