All the vegetables you can fit inside an egg white omelette, folded over and served hot. Lean, colorful, and packed with protein — the dieter's breakfast of choice.
Heat 1 tsp olive oil in a nonstick skillet over medium heat until it shimmers but does not smoke.
Add the chopped onions, red bell pepper, and mushrooms. Sauté over medium heat for 2–3 minutes until softened, stirring occasionally.
Toss in the baby spinach and cherry tomatoes, and cook for 1 more minute until the spinach wilts and tomatoes just blister. Remove all vegetables from the skillet and set aside.
Wipe the skillet clean, lower heat to medium-low, and pour in the beaten egg whites. Let them cook undisturbed until the edges begin to set (about 1–2 minutes).
Spread the sautéed vegetables evenly over one half of the omelette, season with salt and black pepper, then gently fold the omelette in half with a spatula. Cover and cook for another 1–2 minutes until the egg whites are fully set but still moist inside. Serve hot.