Step 1

Pour the Prosecco or Champagne into a saucepan and bring to the boil.

Step 2

Boil for 4 minutes to reduce by half.Pour into a jug.

Step 3

Melt the butter in a frying pan over a low heat. Add the shallots and sauté until soft.

Step 4

Remove from the heat and stir in the flour.

Step 5

Slowly add the prosecco or champagne, stirring well.

Step 6

Place back on a low heat and stirring constantly, simmer for 3 minutes. Add the cream or yogurt and bring to the boil. Boil for 2 minutes. Add the dill and stir well.

Step 7

Season to taste and simmer for 4 minutes.

Step 8

If using, add the capers.