Melt the butter in a saucepan over low to medium heat.

Finely chop the garlic and add it to the melted butter.

Stir in the flour until well combined and the mixture forms a roux. Remove the saucepan from the heat.

Gradually whisk in the chicken stock, cream, and white wine until the sauce is smooth.

Return the saucepan to medium or medium-high heat.

Continue stirring until the sauce thickens.

Bring the sauce to a boil.

Add the mustard powder, salt, and pepper to taste.

Add the uncooked prawns to the sauce.

Cook the prawns for approximately 5 minutes, or until they turn pink and are cooked through.

Stir in the chopped parsley.

Serve hot over your favorite rice.