Step 1

Fill a large bowl with ice water. Thinly slice the radishes and fennel (use a mandoline if you have one), add to the water, and let soak for 10 minutes to crisp them up; drain and pat very dry.

Step 2

Whisk the honey, vinegar, mustard, salt, and pepper in a large serving bowl. Whisk in the olive oil to make a smooth dressing. Add the radishes, fennel, and watercress, and toss to coat. Sprinkle with the pistachios and toss.