1)To butterfly roast, cut down the middle, stopping 1/2 inch from teh bottom. Lay open and make simialr cuts in both sides, again cutting nearly through. (you should end up with four loosely attached sections). Start at center and pound flat (1/2-3/4 inch thick).

2)Cook bacon, reserving drippings in skillet. Cook onions, carrots, and garlic in drippings until tender, remove from heat. Crumble bacon and stir in bacon and basil.

3)Spread mixture on flattened roast. Roll roast from short side, securing with toothpicks or string. Roast in a 325°F oven for 1 1/2 hours (140°F) for rare, or about 2 hours (160°F) for medium. Remove from oven and let sit for 15 minutes, carve into slices.