Steps
1. In a bowl, beat the egg and add the chili powder, salt, and pepper.
2. Heat a non-stick skillet over medium heat and scramble the eggs until fully cooked.
3. In a separate bowl, mix mayonnaise with the chopped onions.
4. Spread the mayonnaise mixture on one side of each slice of bread.
5. Place the scrambled eggs on one slice and sprinkle the grated cheese on top.
6. Close the sandwich with the other slice of bread, mayo side down.
7. Heat the skillet again and add butter. Toast the sandwich on both sides until golden brown and the cheese melts.
8. Cut in half and serve warm.