expression, ichidan verb
thicken; add thickness
Used for cooking when adding starch, roux, or other agents to give a liquid body or viscosity. Often appears in recipes and food descriptions.
スープにとろみを付けるために片栗粉を加えた。
I added potato starch to the soup to thicken it.
カレー
To thicken curry, it's good to fry flour first and then add it.