Heat broiler to high. Line a baking sheet with foil. Place peppers on the baking sheet and broil until totally charred on all sides. Use tongs to keep rolling the peppers to get all sides blackened.
Wrap the peppers up in the foil and let cool completely. When cool, slice open and remove seeds. Catch some of the juices over a bowl. Using the back of a knife scrape the inside of the peppers to completely clean. They are slippery. You don't have to remove every bit of charred skin. It's ok to keep a little on.
Chop the peppers in the bowl that you caught the juice.
Add finely diced red onion, jalapeno, lime juice, salt to taste.
Cover and let sit overnight in the refrigerator.
The next day...blend all cheeses. Add the peppers. Mix well.
Top with diced tomatoes and little more grated cheese.
Bake at 375 for about 15-20 minutes or until bubbly and slightly browned. Pop under the broiler for another minute or two if you want a crispier top.