Prep your base. Heat the coconut oil in a large pot over medium heat. Add the onion and cook until soft and translucent, about 5–7 minutes, stirring occasionally so it doesn’t brown too quickly.
Build the flavor. Add the garlic and ginger. Cook for 1 minute until fragrant.
Stir in the red curry paste (or curry powder), cumin, turmeric, and chili flakes. Toast the spices for 30 seconds to wake them up.
Add the main ingredients. Stir in the sweet potatoes, red lentils, coconut milk, diced tomatoes, and vegetable broth. Add the soy sauce or tamari.
Mix well to combine.
Simmer gently. Bring to a light boil, then reduce to a simmer. Cover and cook for 20–25 minutes, stirring every 5 minutes. The lentils should be soft and the sweet potatoes tender but not falling apart.
Adjust the thickness. If the curry is too thick, add a splash of broth or water.
If it’s too thin, simmer uncovered for another 5 minutes until it reaches your preferred consistency.
Balance the flavors. Stir in the lime juice and maple syrup, if using. Taste and adjust with more salt, lime, or chili for heat. The flavors should be warm, bright, and well-rounded.
Serve. Ladle the curry over rice or with naan.
Garnish with chopped cilantro and an extra squeeze of lime. Enjoy warm.