High-Protein Zucchini Omelet

Bahan-bahan (1 porsi)

• 1 teaspoon olive oil
• 1/4 cup red onion (chopped)
• 1 cup zucchini (diced into matchsticks)
• 1 large egg
• 3/4 cup egg whites
• 2 tablespoons Parmesan cheese (grated or shredded)
• 1/4 teaspoon kosher salt
• fresh black pepper (to taste)