Add everything except spinach + lime: Lentils, coconut milk, broth, garlic, ginger, curry paste + spices, carrots + sweet potato. Stir lightly.
Cook on LOW for 6–8 hours (ideal) or HIGH for 3–4 hours. Lentils should be tender but still intact—not mushy. Add red peppers with ~1h of cooking time remaining.
Stir in spinach until wilted (5–10 min). Add lime juice. Taste and adjust salt.