Onions: onions are used finely or coarsely chopped, sliced or pureed. The properties of onion to the main ingredients of the curry are important. Because this will determine whether there is a sweet element in the taste as well as the thickness of the gravy will be.
Yoghurt: yoghurt gives body & a creamy texture to a curry, but is more important as a “souring “agent.
Coconut milk: coconut flesh is ground to a paste or flesh is grated &soaked in warm water to extract coconut milk.
Nuts& seeds: ground almonds, cashew nuts, peanuts are some times used in curries, not only for there thickening quality but also for their flavor.White poppy seeds: other ingredients, primarily used as thickening agent in some moghali & hyderabadi dishes, &in the cuisine of Muslim communities of Mumbai & southern India.
Mustard seed: mustard seeds are as thickeners to a lesser extend, only in a few recipe are ground mustard seeds are used widely.
Pumpkin or melon seed: ingredients used in the court recipes of Delhi called char magaz. Sesame seed: white sesame seed gives a unique flavor to the food. The seeds are used in smaller quantities & therefore not as a thickening agent on their own,