I cheat with this and use a sachet of curry sauce. Actually, I use two, and fill my slow cooker, which does us several meals (it freezes well).
I start off by putting 2 sachets worth of Passage to India Korma curry 
in the slow cooker and turn it on to high to start warming.
Then I chop up half a butternut pumpkin into bite size pieces (maybe about 2-3 cups worth of chopped pumpkin), and a sweet potato, and adding that and 500g diced beef to a frying pan, and cook that (no oil) until the meat has browned. You could of course leave out the meat for a vegetarian meal.
Put the cooked stuff into the slow cooker, with a chopped zucchini, 2 chopped carrots, a tin of drained (and rinsed) chickpeas and a tin of drained (and rinsed) lentils. You can add other veg if you like. Don’t add any extra liquid, as the slow cooking will add moisture.
Leave that cooking for several hours until the pumpkin is soft. I like to mix a can of coconut milk through once it’s cooked. Serve on rice, with some roti
