This is a classic Algerian 'salad' dish. You can either grill the tomatoes & peppers over an open flame, deep fry them or roast them. My family loves this recipe & we always mop it up with fresh bread! You can also serve this as part of a mezze selection. The vinegar is of course optional but it acts as a flavour enhancer so I do recommend at least trying a little of the salad with a few drops of vinegar on!