Heat a large non-stick skillet over medium heat for about 2 minutes. Add 1 tablespoon of butter and let it melt.

Crack a large egg into the skillet, season with salt and pepper, and cook for 3–4 minutes until the whites are set and the yolk is runny.

Lay another tortilla flat and sprinkle half of the shredded cheese evenly over it.

Slide the cooked egg onto the tortilla, add sliced avocado, then sprinkle the remaining cheese and cover with a second tortilla.

Cook the assembled quesadilla in the skillet for about 2–3 minutes until the bottom is golden brown, then flip and cook the other side.

Cut into wedges and serve hot with your favorite salsa or sour cream.