Start by thoroughly washing the baby spinach and drying it completely using a salad spinner or clean kitchen towels. It is vital that the leaves are dry so the dressing clings to them instead of sliding off. If you are starting with a whole pomegranate, score the skin and submerge it in a bowl of water to break it apart, which prevents the juice from staining your holiday outfit while you collect the seeds.
Place the walnut halves in a small dry skillet over medium heat. Shake the pan frequently for about three to five minutes until the nuts become fragrant and slightly golden. Remove them from the heat immediately and let them cool, as they can burn quickly if left in the hot pan. This step adds a deep, smoky flavor that elevates the entire dish.
In a small glass jar or a medium mixing bowl, combine the extra virgin olive oil, apple cider vinegar, Dijon mustard, honey, salt, and black pepper. Whisk vigorously until the mixture is emulsified and creamy. You can also put the ingredients in a jar with a tight lid and shake it forcefully until well combined.
Place the dried spinach in a large serving bowl. Add the thinly sliced red onions and half of the pomegranate seeds and walnuts. Drizzle about two thirds of the dressing over the top and toss gently to coat every leaf. Using your hands or large tongs helps ensure the delicate spinach does not get bruised during the process.
Top the tossed salad with the remaining pomegranate seeds and toasted walnuts for a beautiful presentation. Drizzle the remaining dressing over the top if the salad looks a little dry, or serve it on the side. Serve immediately while the greens are crisp and the nuts are crunchy.
