Thinly slice the celery on a bias into 1/4-inch pieces—this creates more surface area for the dressing to coat and looks more elegant on the plate. Pit and slice the dates into thin slivers. Roughly chop the pistachios, keeping some texture. Drain the mandarin oranges if using canned segments, reserving a tablespoon of juice to add brightness to the dressing. Measure out the fresh parsley and celery leaves, tearing any large parsley leaves by hand.

In a large bowl, whisk together the olive oil, freshly squeezed lemon juice, honey, salt, and black pepper until the honey dissolves completely and the dressing emulsifies slightly. The honey acts as a natural sweetener that balances the acidity and helps bind the flavors together. Taste and adjust seasoning—I like to add an extra squeeze of lemon juice here to ensure the dressing has enough brightness to cut through the richness of the nuts and dates.

Add the sliced celery, celery leaves, and parsley to the dressing and toss gently to coat evenly—the fresh celery leaves give a concentrated herbal punch that lifts the entire salad. Fold in the date slivers, mandarin orange segments, and chopped pistachios, being careful not to crush the fruit or nuts. For the best texture, I assemble this salad just before serving to keep the celery crisp and prevent the pistachios from softening. Taste one final time and adjust with a pinch of extra salt, a squeeze of lemon juice, or a few more date slivers if you want more sweetness.