Heat oil in a large skillet or pot over medium heat. Add onion, garlic, and ginger, cooking until fragrant and lightly golden.
Add chicken pieces, season with salt and pepper, and cook until lightly browned.
Stir in curry powder, coating the chicken. Let it toast for 1 minute to release the flavors.
Add pumpkin puree and coconut milk. Stir well to combine, then bring to a gentle simmer.
Simmer for 15–20 minutes, stirring occasionally, until the chicken is cooked through and the sauce thickens.
Taste and adjust seasoning. Garnish with fresh cilantro and, if desired, a sprinkle of red chili flakes.
Serve warm with rice, naan, or quinoa.