Heat avocado oil in a large skillet over medium heat.
Add chopped onion and sauté until soft, about 3-4 minutes.
Stir in garlic and ginger and cook for another minute.
Add curry powder, turmeric, salt, and pepper. Stir to combine.
Pour in coconut milk and water or chicken stock. Bring to a simmer.
Add the chopped turkey and fish sauce if using. Simmer for 10-12 minutes, stirring occasionally.
Stir in lime juice, adjust seasoning if needed.
Serve hot over steamed rice, garnished with fresh cilantro.