1. For Roasted Onion Bowls: Slice the top off each onion and ¼ inch down. Carefully slice the onion bottom just enough that it stands up. Using a butter curler, hollow out onion in small, circular motions. Be sure to leave 2-3 layers of onion around the outside and stop ¾ inch from the bottom. Rub each onion with olive oil and bake for 15 minutes at 325 degrees. Cool.
2. Mix hot mashed potatoes with Roquefort and hot caramelized onions. Keep warm. Before serving, heat onion bowls in an oven set at 375 degrees for 2 minutes. Fill onions with potato mix and top with breadcrumbs. Return stuffed onions to 375-degree oven for 5 minutes. Serve hot.