Add the following ingredients to the slow cooker- chickpeas, orange bell pepper, onion, potatoes, carrots, ginger, garlic, lemongrass, water, vegetable broth, curry powder, garam masala, turmeric, cumin, and coriander. Stir. Cover and cook on high for 3 1/2 hours (or 5 1/5 hours on low heat).
After the time is elapsed, test the carrots and potatoes to make sure they are almost soft (they will still have a little bite to them).
Then add the coconut milk (only the cream on top- not the liquid), sweet peas, sea salt, and golden raisins. Stir. Mix 1 tablespoon amaranth powder (or cornstarch) with 3 tablespoons cold water and add to the slow cooker. Stir.
Set the slow cooker back to Low heat. Cover and cook an additional 15 minutes. Test the potatoes/carrots for doneness (if they aren't soft, cook an additional 15 minutes) and set slow cooker to Warm. It's best to let this sit for about 30 minutes before serving so it thickens even more.
This recipe makes roughly 8 cups curry. The sauce will be a bit thin at first, but will thicken quite a bit over time. Serve over rice and/or with naan bread. Store in an airtight container in the fridge for 3-4 days.