Step 1

Place potatoes in a large pot with enough water to cover them. Bring to a boil over high heat and cook 15 to 20 minutes, or until fork-tender. Drain and let cool; place in a large bowl.

Step 2

In a medium bowl, whisk oil, lemon juice, vinegar, garlic, salt, and pepper.

Step 3

Add spinach, tomatoes, onion, and lemon zest to the potatoes. Pour vinaigrette over mixture and toss until evenly coated. Serve immediately or cover and refrigerate until ready to serve.