Heat oil in a large skillet or pot over medium heat.
Add chopped onion and cook until soft and golden, about 5 minutes. Stir in garlic and ginger, cooking for 1 more minute until fragrant.
Add the seasonings and stir for 30 seconds to 1 minute to toast the spices and release their flavor.
Add the remaining ingredients and stir everything together. Bring to a gentle boil.
Reduce heat to a simmer, cover, and cook for 20–25 minutes, or until the sweet potatoes are tender.
Taste and adjust seasoning as needed. Add a squeeze of lime or lemon juice if desired, and garnish with cilantro for a bright finish.
Serve over basmati rice and with garlic naan for a filling and delicious meal.