Take finely chopped onions, tomatoes and mayonnaise and mix them well in a bowl.

Now add tomato sauce in it.

Take nachos and put in a large plate.

Now add the the mixed material into the nachos.

Spread the mozzarella cheese over it.

Keep it in microwave for 3-4 minutes till the cheese get melted.

The cheesy nachos are ready to serve. Serve hot.