Preheat oven to 425°. In a small bowl, mix vinaigrette, 2T rosemary and garlic. Brush roast with 1/2 the mixture. Roast for 30 minutes (should be 130°). Mix preserves into remaining vinaigrette.

In a saute pan over medium heat, cook the onions and bread in butter for 30 minutes. Stir in 1/4C orange juice, 1/2 tsp zest, cranberries and remaining rosemary. Transfer to the center of the roast. Heat broiler; broil roast for 5 minutes. Let sit for 15 minutes before carving. Serve with preserves mixture.