Flour is the key component in a roux. The only difference is cooking the flour in some butter to remove the raw flavor. FYI, that combination is called a béchamel sauce.
Edit: actually béchamel had some milk also, but yeah
Edit: actually béchamel had some milk also, but yeah
AFAIK, the cheese I'm using doesn't have anything particularly special (some cheap hard cheddar). I don't even grate it, just chop it up a little before adding it to the water.