Heat coconut oil in a large saucepan over medium heat. Add the red onion and sauté until soft.
Stir in garlic and ginger and cook for another minute until fragrant.
Add curry powder and turmeric. Cook, stirring, for 1 minute.
Pour in chopped tomatoes and cook for 5 minutes, stirring occasionally.
Add both types of beans, green beans, and half of the coconut milk. Simmer for 15–20 minutes until the green beans are tender.
Season with lime juice, salt, and pepper to taste.
For the drizzle, mix the remaining coconut milk with a little chopped cilantro.
Serve the stew in bowls and drizzle with the coconut-coriander mixture. Garnish with extra cilantro if desired.