Wash and drain chard; trim off tips of stems and discard. Finely sliver remaining stems; also finely sliver leaves, but keep separate.
In a 5 to 6-quart pan, combine stems, 3 tablespoons water, and 1 tablespoon vinegar. Place on high heat and stir often until stems are crisp and lighter in color (3-4 minutes). Pour from pan into a bowl. (Stems may darken slightly on standing.).
Set aside 3 cups of the slivered leaves. Rinse pan and add 2 tablespoons water and remaining leaves; stir over high heat just until barely wilted, about 3 minutes. Pour from pan and lt cool.
Cut apples in quarters, core, and thinly slice. Reserve 4 slices for garnish, then cut remaining apple into thin slivers. Mix slices and slivers with 5 tablespoons vinegar and oil. To hold until next day, cover stems cooked leaves, raw leaves, and apples separately; chill.
To serve, mix stems, raw and cooked leaves, and slivered apples together n a bowl; season to taste with salt and pepper. Sprinkle salad with pecans and top with apple slivers. To transport, cover and carry in an insulated chest.