Turn heat to low, and add flour, all at once.
Add the flour and cook over low heat for about three minutes.
If needed, continue adding flour a little at a time.
Add flour as you need, but only in small amounts.
Turn down the heat to medium and add the flour.
Remove from the heat and add the flour in one go.
Add the flour and stir over the heat for 2-3 minutes.
Add the flour, a little at a time, until smooth.
Add more water or flour as needed to achieve the right consistency.
Some people add flour or cornmeal, but I do not find it makes a difference.