Mix the eggs in a bowl,then coarsely grate the cheese into the mixture.
Roughly chop the garlic and chilli.
Heat the oil in a non-stick frying-pan. Add the garlic and chilli, stir for 30 seconds. Add the egg mixture, let it spread out evenly. Turn the heat off, put a lid on, then cook for about 5 minutes.
When the surface of the omelette is no longer runny (but not solid yet), add the spinach and put the lid on again for a couple of minutes.
Fold the omelette in half and keep cooking for another minute or so, until the spinach has wilted.
Serve warm or let it cool and cut into bite sided squares.