Preheat your oven to 400°F and lightly spray a 12-cup muffin pan with non-stick cooking spray.

Evenly divide the chopped onion, green pepper, and chicken ham among the muffin cups.

Sprinkle shredded cheddar cheese over the top of each cup.

In a mixing bowl, whisk together the eggs, half and half, salt, and pepper until well combined.

Pour the egg mixture into each muffin cup, filling them almost to the top.

Bake in the preheated oven for 20–22 minutes, or until the egg muffins are set and lightly golden.

Remove from the oven and let cool slightly before serving. Garnish with sliced green onions if desired.