Wash the spinach leaves then chop quite finely and leave to drain in a colander.
Heat the oil in a large frying pan and fry the cumin seeds and the red chillies until the chillies darken.
Add the garlic and onion and continue to fry until they soften. Season then add the spinach.
Mix well and cook over a low heat until the spinach is done. This will vary according to the type of spinach you are using- young spinach will take about 3-5 minutes but older spinach may take 10 minutes or so.