[madcat]

1 tbsp vegetable oil
2 onions, very finely chopped
2 tsp yellow mustard seeds
3 tbsp madras curry paste
1 green chilli, halved lengthways
400g can chopped tomatoes
3 tbsp ground almonds  OR  (and I prefer this) the same of creamed coconut
4 tbsp low-fat natural yogurt, plus extra to serve
1kg (peeled weight) raw beetroot, peeled, halved and thickly sliced, or fork sized chunks
 
1.   Heat the oil in a large lidded pan, stir in the onions and cook for 8 mins until soft. Tip in the mustard seeds and cook for 1 min until toasted. Stir through the curry paste and sizzle for 3 mins.
2.   Mix the beetroot through the spicy onions, then add the chilli, tomatoes and 2 cans of water, plus coconut cream if using. Cover and simmer for 30 mins, stirring occasionally, until the beetroot is tender. Remove the lid, turn up the heat and cook until the sauce is thick. 
You can do this stage in a slow cooker - which works really well because it gives time for the sauce to blend properly. Use a bit less water so you dont need to do the evaporate off bit. 
3.   Take off the heat, then stir through the almonds if using, yogurt and some seasoning. Top with yogurt and serve with basmati rice, if you like.