Spread the tortilla chips over a microwave-safe plate in a single layer.
Pop in the microwave and cook on high for 30 seconds to warm through.
Remove from the microwave and spread small dollops of the sour cream all over.
Add jalapeño peppers if using.
Top with a layer of grated mozzarella cheese, spread evenly over the top.
Pop back in the microwave and cook again for 30 seconds to 1 minute. Watch to see when the cheese starts to bubble - that's when they are ready.
Leave to stand for a minute before serving as there may be hot spots.
Serve with guacamole and / or salsa for dipping.