Peel the ginger and cut into fine strips about 1cm long.
Heat the oil gently and add the onion, cooking until translucent.
Add the sweetcorn, ginger and garlic and cook slowly over a low heat for about 12 minutes.
Add tomato purée, cumin, Thai paste, red chilli and tamarind and stir. Add about 50 - 100ml water to loosen mix and continue cooking for a further 8 - 10 minutes until the mixture thickens slightly and the sweetcorn is just cooked. It's nice to keep some of the crunch to the corn.
Notes
Serve with chapati, rice or as a side dish to a meat curry.