Preheat oven to 350°.
Remove white papery skin from garlic head (do not peel or separate the cloves). Wrap in foil. Bake at 350° for 1 hour; cool 10 minutes. Separate cloves; squeeze to extract garlic pulp. Discard skins.
Prepare grill or broiler.
Place tomatoes and peppers on a grill rack or broiler pan coated with cooking spray; grill or broil for 15 minutes or until skins are blackened, turning occasionally. Peel tomatoes and peppers.
Place half of garlic pulp, half of tomatoes, and half of peppers in a blender, and process until coarsely chopped. Pour garlic mixture into a bowl. Repeat procedure with remaining garlic pulp, tomatoes, and peppers. Stir tomato juice and lime juice into garlic mixture.
Note: Serve remaining salsa with baked tortilla chips or over grilled fish.