Put the red lentils in a bowl of cold water and set aside for at least 30 - 60 minutes if possible. Alternatively pour hot water over the lentils as you start to prepare the curry.
Place the coconut oil in a fry pan over a medium heat.
Once the coconut oil has melted, add the onions to the fry pan and cook for 8 minutes, or until the onions have browned.
Add the garlic and ginger to the fry pan and cook for 1 minute.
Whilst the onions are cooking, add the korma curry paste and the coconut milk to the slow cooker insert and stir to combine.
Scrap the onion, garlic and ginger mixture into the slow cooker insert.
Drain the lentils and add them to the slow cooker insert together with the drained chickpeas.
Thoroughly stir the onions, lentils and chickpeas through the curry base.
Nestle the chicken thighs in the curry base, pushing the thighs into the liquid so they are covered.
Push any rogue red lentils under the liquid as they will not cook unless covered.
Place the lid on the slow cooker and cook on Low for 7-8 hours or on High for 4-5 hours.
Just prior to serving, scatter the chopped coriander over the chicken, and try to mix it into the curry sauce as you serve the curry.
Serve with rice and lime wedges if desired.