Preheat oven to 375 degrees F. Whisk together the 4 whole eggs with the 2 egg whites and season with salt and pepper.
Heat small skillet with the olive oil. Sauté the onion, mushrooms, and broccoli ~3-5 minutes.
Add the egg mixture and quickly scrape all sides of pan to evenly distribute egg and veggies.
Remove from heat and finish cooking in the oven for 5 to 8 minutes or until egg is fully cooked. Garnish with chives (optional)