Combine the flour and 2 Tbl. of water in a glass and stir with a fork until there are no lumps. Or you can use a shaker cup with a lid and sake this mixture until combined with no lumps.
In a saucepan, combine the beef juice and water as needed. Bring to a boil. Slowly pour in the flour and water mixture whisking the entire time until combined. Cook a minute or two until thickening (stirring constantly).
Remove from heat and add the half and half. Salt and Pepper to taste.