In a medium mixing bowl, whisk together eggs. Add salt and pepper.
Add three tablespoons of olive oil to a non-stick skillet. Heat skillet over medium-high heat. Reduce heat and add the minced onions; sauté until soft, about 1-2 minutes. Add whisked egg mixture. Gently move the eggs from side to side and the mixture begins to settle. Add American cheese slices one by one and melt them into the eggs.
Cook eggs until the are nice and fluffy and minimal liquid is left.