Indian restaurants often throw me off. Usually I must ask if the bread is not buttered but the bread is sometimes made with milk and sometimes not. I know some words, like "paneer," refer to dairy products but often make a mistake and order something with butter in it. What is your best method for ordering vegan in an Indian restaurant?

If the answer is "just ask," actually learning how you ask would help since it is difficult to sound educated enough. But I am also interested in being educated enough about the cuisine to just know for myself since it is often vegetarian and excellent.