To make the apple dressing, mix apple juice, apple cider vinegar, chopped onion and lemon juice. Taste and adjust. If too sweet, add some lemon juice; if too sour, add some apple juice. Boil a pot of water, cook spinach for about 1 minute, then drain and let cool. Note? If you want to impress the guest, follow the next steps to make the dish pretty. Otherwise, simply put the spinach in a serving bowl and pour sauce over the spinach. Place your favorite cookie cutters on a place, press the spinach into the cookie cutters. Wipe off excess water on the plate. Spoon some apple dressing on the spinach. Press down on the spinach with one hand while removing the cookie cutter with another hand. Serve remaining dressing on the side or pour around the spinach. Garnish with lemon wedge or apple slices.