In a large bowl, whisk together the eggs, milk, salt, and pepper.

Heat olive oil in a non-stick skillet over medium heat.

Add the bell pepper and onion to the skillet and sauté until softened, about 5 minutes.

Add the shredded fried chicken to the skillet and cook for another 2 minutes.

Pour the egg mixture into the skillet and stir to distribute the ingredients evenly.

Cook the frittata for 10-15 minutes, until the edges are set but the center is still slightly jiggly.

Sprinkle the shredded cheddar cheese on top of the frittata and cover with a lid or aluminum foil.

Continue cooking for another 5 minutes, until the cheese is melted and the center of the frittata is set.

Remove from heat and let the frittata rest for a few minutes before serving.

Slice into wedges and serve hot.