Prepare dressing by whisking together all ingredients in a glass or other non-reactive bowl. Taste and adjust seasonings, as desired. Transfer to a serving container and set aside.
Mix the spinach and arugula, arrange on a serving platter and top with sliced fennel, strawberries, and Feta cheese.
Serve immediately with chilled salad plates and dressing on the side. Enjoy!
Notes
Note: If preferred, toss the spinach and arugula with the salad dressing prior to arranging on the platter.