Heat the oil in a large pot over medium heat.
Add the chopped onion and sauté until translucent.
Stir in the minced garlic and ginger, cooking for another minute.
Mix in the red curry paste and sauté until fragrant.
Add the chicken pieces and cook until lightly browned.
Pour in the coconut milk and stir to combine.
Incorporate tamarind paste, sugar, and salt; stir well.
Cover the pot and let it simmer for 30 to 40 minutes, until chicken is tender.
Taste and adjust seasoning as necessary.
Serve hot, garnished with fresh cilantro.
