Place bisto and flour in a bowl and add a cup of water.
Blend these items until smooth. I use a electric hand mixer, its just easier.
Slowly add this mixture into the boiling water and onion soup mix. Stir constantly, it will begin to thicken right away. If it is too thick for you just add some more water to the pot. Keep it on med. heat for about 5 more min. so the flavour can cook through.
If it becomes lumpy just strain it into another pot.
And its ready to serve.