Heat oil or butter in a pan
Add chopped onion and cook until soft
Add minced garlic and ginger
Stir in curry powder or curry paste
Cook for 1 to 2 minutes
Add flour if you want a thicker sauce
Slowly pour in broth, water, or coconut milk
Stir until smooth
Add salt and pepper
Simmer until the sauce thickens
Add optional ingredients like tomato paste, yogurt, cream, or chili
Taste and adjust seasoning
Serve hot