Over the open flame on your stove, roast the bell peppers and the hot pepper until the skin is all charred and black. Immediately place in a bowl and cover tightly with plastic wrap. Leave for 15-20 minutes. The peppers will sweat, making it easy to remove the skin.
Remove the skin from the pepper. Cut out the stem and the core. Slice the bell peppers into 2" wide strips. Thinly slice the hot pepper. Set aside in a bowl.
Coarsely chop the garlic. Sprinkle the salt on top and continue to chop the garlic finely until it becomes almost a paste. Add to the peppers.
Add olive oil and mint. Stir to combine. Cover and leave in refrigerator overnight.
Add balsamic vinegar and leave for 15 minutes to take some of the chill out before serving.