Preheat oven to 425°F.
Line a 15x10x1-inch baking pan with foil. On the prepared pan, place tomatoes, cut side down.
Peel away outer skin from garlic. With a knife, cut off the pointed top portion, leaving the bulb intact but exposing the individual cloves. Add to pan with tomatoes. Drizzle garlic with oil. Roast 25 to 30 minutes or until tomato skins are charred and garlic is soft. Press to remove garlic paste from individual cloves.
In a food processor or blender, place garlic, jalapeños, and salt. Cover and process or blend until finely chopped. Add half the tomatoes; cover and process or blend with a few pulses until coarsely chopped. Transfer to large mixing bowl.
Add remaining tomatoes; cover and process or blend until coarsely chopped. Stir into tomato mixture in bowl.
Stir onion, cilantro, and lime juice into tomato mixture until combined. Cover and chill several hours to blend flavors. Serve salsa with red sweet pepper and/or tortilla chips.