Step 1

Whisk ½ cup extra-virgin olive oil, 3 Tbsp. fresh lemon juice, 1 Tbsp. Dijon mustard, 1 Tbsp. finely grated Parmesan, and 2 tsp. honey in a medium bowl until emulsified. Season dressing with kosher salt and freshly ground pepper.

Step 2

Using a small knife, remove peel and white pith from 6 mixed oranges (such as Cara Cara, blood, and navel); cut crosswise into ¼"-thick rounds. Combine oranges, 1 medium fennel bulb, thinly sliced, 1 medium red onion, thinly sliced, and 5 oz. arugula in a large bowl. Pour dressing over and toss to coat. Taste and season with more salt if needed.

Step 3

Arrange salad on a platter. Top with shaved Parmesan.