In a medium mixing bowl, combine olive oil, lemon juice and zest, honey, and salt and pepper. Whisk until emulsified and set aside.

In a large salad bowl, chop Romaine lettuce and add. Thinly slice red onion and combine with lettuce. Add grated Parmesan and crushed red pepper flakes.

Drizzle lemon dressing over the salad ingredients and ensure even distribution.

Gently toss all ingredients together for about 30 seconds until coated.

Transfer salad to a serving platter or bowls and serve immediately.