01 - Heat a large saucepan or Dutch oven over medium heat. Add a splash of oil and sauté the onion until soft and translucent, about 5 minutes.
02 - Add the garlic and ginger; cook for 1 minute until fragrant.
03 - Stir in the Rogan Josh curry paste, cumin, coriander, cinnamon, smoked paprika, and chili powder. Cook for 2 minutes, stirring, until the spices are aromatic.
04 - Add the chopped tomatoes and cook for 3 minutes until they begin to break down.
05 - Add the pumpkin cubes and rinsed lentils. Stir to coat with the spice mixture.
06 - Pour in the coconut milk and vegetable broth. Bring to a gentle boil, then reduce the heat to low.
07 - Cover and simmer for 25-30 minutes, stirring occasionally, until the pumpkin is tender and the lentils are cooked through.
08 - Season with salt and black pepper to taste. If the curry is too thick, add a little more broth; if too thin, simmer uncovered for a few more minutes.
09 - Serve hot, garnished with fresh coriander and lemon wedges, alongside steamed rice or naan if desired.