1) Heat the oil in a large saucepan, add the onions and cook until soft.
2) Add the mustard seeds and fry for 1 min until toasted.
3) Stir in the curry paste and fry for a further 3 minutes.
4) Add the beetroot, the chilli, tomatoes and enough water to cover.
5) Bring up to the boil then turn down and simmer, with a lid on, for 30 mins, stirring occasionally, until the beetroot is tender.
6) Remove the lid, turn up the heat and boil until the sauce has thickened.
7) Take off the heat and stir through the almonds and 4 tbsp of the yogurt.
8) Season to taste and serve topped with the rest of the yogurt