Soak the mung beans in plenty of water overnight. The next day, cook them for about 30 minutes until they are slightly breaking apart but still retain some texture.
Chop the bell pepper, garlic, ginger, and onion into small pieces. If using fresh herbs, cut them up as well.
Heat some oil in a pot, add the chopped onion, and let it brown for 3-4 minutes.
Next, add the bell pepper, ginger, and garlic, and let it cook for another 5 minutes.
Before adding the liquid ingredients, mix in all the prepared spices for the curry. Adding the seasonings can dry the vegetables slightly, making them prone to burning. Stir frequently for 2 minutes to prevent sticking or burning.
Add the cans of coconut milk and chopped tomatoes, along with the cooked mung beans. If you haven't done so already, remember to season generously with salt throughout the cooking process.
Add a stick of cinnamon and let the curry cook for 20-30 minutes until everything is smooth and combined, and the mung beans have soaked up the creamy, flavorful goodness. Before serving, let it cool slightly, as it will thicken off the stove and develop a more intense flavor. Plate it with rice or naan bread, and squeeze a lemon slice over it. Enjoy!