The organization fights for 'basic' human rights [=the rights that all people should have] throughout the world.
The restaurant is 'getting back to basics' in terms of food, using fresh ingredients to make simple, good food.
These ingredients are a 'basic' part of Thai cooking. = These ingredients are 'basic to' Thai cooking.
(..) you hear? I want an answer. - Objection. - Watch it, counselor. I'm trying very hard, Judge. Try harder, counselor. It seems basic to our constitutional principles that the extent of the right to assemble, and demonstrate and march along the highway in a peaceful manner (..)2014 Selma
(..) militant Malcolm X types. So... I wanna help. Tell me how. Well, Mr. President, I'm here to speak specifically about the denial of a basic American right for the Negro citizen. The right to vote. Well... Technically... Technically, we already have it. Yes, Mr. President. (..)2014 Selma