Crack the eggs into a mixing bowl. Whisk gently with a fork until the whites and yolks are just combined. Do not over-whisk, as this can make the eggs dense.
Heat olive oil in a skillet over medium-low heat. Allow the oil to warm but not smoke.
Add the diced onion and cook for 2–3 minutes until soft and translucent.
Stir in the garlic and cook for about 30 seconds, just until fragrant.
Add the cherry tomatoes and sprinkle with dried oregano, salt, and black pepper. Cook for 2–3 minutes until the tomatoes soften slightly and release juices.
Reduce the heat to low. Pour the whisked eggs into the skillet over the vegetables.
Let the eggs sit undisturbed for about 20–30 seconds until they begin to set at the edges.
Gently push the eggs from the edges toward the center using a spatula, creating soft curds.
Continue cooking slowly, stirring occasionally, until the eggs are just set but still creamy.
If using optional ingredients like feta or spinach, add them during the final minute of cooking.
Remove the skillet from heat immediately to prevent overcooking.
Garnish with fresh parsley and an extra sprinkle of black pepper. Serve warm.