In a medium mixing bowl or small jar, combine the champagne vinegar, Dijon mustard, honey, and salt. Use a Microplane to grate the garlic into the dressing. Whisk or shake to combine. Add the olive oil and whisk or shake to emulsify. Alternatively, process the ingredients together in a small food processor until emulsified.
For the Holiday Salad
Thinly slice the red onion. Place in a shallow bowl and cover the slices with cold water. Let soak for 10 minutes and then drain.
Prepare the oranges by cutting off the ends of each orange. Use a knife to cut away the orange skin, working from the top to the bottom, being sure to remove the entire white pith. With a sharp thin knife, carefully cut between the membrane to the center of the orange to remove a segment.
In a dry skillet over medium-low heat, add in chopped nuts. Toast for 3-4 minutes, tossing regularly. Remove from skillet and let cool.
Arrange the greens in a large serving dish. Toss the greens with ¼ cup of prepared salad dressing. Scatter orange segments, red onions, and pomegranate seeds on top of greens. Sprinkle with feta cheese and nuts. Serve with the remaining dressing on the side.
Notes
Mixed Greens: I prefer a mix of arugula and baby spring greens for this salad, but spinach works as well. Onions: Soaking the onion is not necessary, but does help to mellow out the sharpness of the onion. Feel free to use shallots in place of the red onion. Champagne Vinegar: If you do not have champagne vinegar, use white wine vinegar in its place. This holiday salad is best assembled immediately before serving. However, all the components can be prepared up to 48 hours in advance. I recommend segmenting the oranges, soaking the onions, toasting the nuts, and preparing the dressing a day or two before serving. Then it is as easy as assembling the salad and serving it to your guests.