Set broiler to high. Line a broiler pan with foil and arrange peppers. Slide under broiler and roast, turning peppers until the skin is blackened all over. Set in a paper bag, seal, and set aside for 10 minutes.

Remove the blackened skin (it will peel of easily), and remove the stem and seeds under cold running water. Pat dry and mince.

In a large bowl, combine minced peppers, cheddar, cream cheese, mayo, red onion, garlic, and rice wine vinegar. Stir until well mixed. Add pepper. Taste, and add sea salt if needed. (I didn't end up adding any.)

Pimento cheese can be served right away, but will be better if given time to chill covered in the fridge. A few hours are great; overnight is even better.