1. Spread, to taste, 4 slices of bread with mustard, and the remaining 4 slices with mayonnaise.
2. Assemble sandwiches, using ¼ of each veggie, one slice of cheese, and two sorrel leaves on each sandwich. Slice each sandwich in half and serve.
3. if you wish to roast your own pepper, place pepper directly on the oven rack and broil a few inches from the element, turning frequently until the pepper is evenly charred. Immediately remove pepper from heat and place in a zip-lock bag, allowing bag to steam with the accumulated heat. When peppers can be handled, (about 15 minutes), strip off skin by hand; core and wash pepper, and cut into strips as desired. Peppers can also be roasted over an open wood or charcoal fire, too.