Doon Shokudo Indoyama is run by a lovely couple who speak fluent English. You have your choice of three delicious curries including a vegan/vegetarian option if you are not much of a meat eater. They also offer an Halal chicken curry made with halal-certified chicken (note that the kitchen is not separated, however). All curries come with a popadom, chapati and great conversation. Also feel free to ask the owner for extra rice if you’re feeling hungry.
The restaurant is located in an enclosed court called Hashigo Yokocho, which is a bit hidden in the back alleys of Matsumoto. There are several other shops here as well.