To a large bowl, thoroughly whisk together the champagne vinegar, lime juice, creme fraiche and olive oil and salt. Add the cubed bread, Persian cucumbers, green bell pepper, tomatillos, scallions, garlic clove, Italian parsley and cilantro. Toss together until all of the ingredients are coated in the dressing. Cover with plastic wrap and transfer to the fridge to marinate for at least 4 hours, ideally overnight.