Step 1

Heat up the oil in a heavy-bottomed pot.

Step 2

Add mustard seeds and curry leaves. Stir them into the oil and allow them to heat up until the mustard seeds start to crackle.

Step 3

Once mustard seeds have been crackling for a few seconds, add the diced onion and fry it on a low heat until almost translucent (for about 5-7 minutes), stirring from time to time.

Step 4

Next add in diced garlic, ginger and chilli. Keep on frying gently for a few more minutes until fragrant, stirring the whole time as they burn easily.

Step 5

Add all of the dry spices to the onion / garlic / ginger / chilli mix and stir them around for a few seconds, making sure they don't burn - if the pan gets too dry, add a splash of water.

Step 6

Stir in canned tomatoes gently (so that they don't burst and splatter) squashing them with a fork once they are in the pan.

Step 7

Next, add in about 480 ml / 2 cups of water.

Step 8

Cover the pot and allow the sauce to come to a gentle simmer. Simmer on a low heat until the tomatoes fall apart and the sauce becomes more uniform, without large tomato chunks in it.

Step 9

While the sauce is simmering, chop up cauliflower into florets and cube the sweet potato.

Step 10

Mix in coconut milk.

Step 11

Season with salt, black pepper and tamarind (or lime juice).

Step 12

Put the cubed sweet potato into the sauce and cover the pot. Allow it to simmer gently in the sauce for about 10 minutes.

Step 13

Add cauliflower florets to the sauce and allow them to simmer for about 5-6 minutes. You could also roast the cauliflower in the oven for that nice char - to do so, coat it in 2 tsp of oil and roast it for about 20 minutes at 200° C / 390° F.

Step 14

Serve on top of rice garnished with fresh coriander and chopped roasted cashews.