Combine all dressing ingredients in a jar. Shake well and set aside.
Thinly slice red onion. If desired, soak in cold water for 5 minutes, then pat dry.
Wash and slice strawberries about 1/4 inch thick.
Add baby spinach to a large serving bowl.
Top with strawberries, red onion, feta, and candied pecans.
Drizzle with dressing just before serving. Toss gently and serve immediately.