If using dried beans, soak overnight and cook until tender.
Heat oil in a pot and sauté onion, garlic, and chilies until soft.
Add curry powder, turmeric, and cumin; cook 1–2 minutes until fragrant.
Stir in tomatoes and water/stock; bring to a simmer.
Add diced potatoes and cooked beans. Simmer 20–30 minutes, or until potatoes are tender and sauce thickens.
Season with salt and pepper.
Garnish with fresh coriander if desired.
Serve hot with rice, pap, or bread.