Step 1

In a mason jar, combine the lemon juice, vinegar, salt and pepper to taste and red onion slices

Step 2

Swirl to coat the onions, then let sit for a couple minutes

Step 3

Place the arugula and fennel in a salad bowl

Step 4

Remove the onions from the mason jar, reserving the liquid in the jar, and place on top of the salad

Step 5

Add the olive oil, Dijon, honey, parsley, red pepper flakes and lemon zest to the mason jar and shake to emulsify

Step 6

Pour the dressing over the salad, top with the Parm (if using) and serve