Heat butter, oil and garlic in a medium frying pan over medium-high heat until butter has melted. Add flour. Cook, stirring for 1 minute or until mixture bubbles.
Slowly add stock, ¼ cup at a time, stirring constantly to prevent lumps forming. Add wine and cream. Cook, stirring for 3 minutes or until sauce boils and thickens. Add mustard, to taste. Season with salt and pepper.
Add prawns. Simmer, stirring for 3 minutes or until prawns are cooked through. Stir in parsley. Serve creamy garlic prawns with steamed rice.
