You need to either create a slurry in a cold liquid, which also works with cornstarch, or you've got to do your gravy in a very wide pan and kind of scatter the flour over the top and then very quickly whisk it in.

You need to either create a slurry in a cold liquid, which also works with cornstarch, or you've got to do your gravy in a very wide pan and kind of scatter the flour over the top and then very quickly whisk it in.