Soak the filleted oranges in their juice and tequila the night before and keep closed in the refrigerator.
Mix the other juices in a punch bowl, add the orange fillets with juice and tequila. As soon as the guests arrive, fill the punch with the sparkling wine and add a few dashes of grenadine, do not stir, just drink.
The punch is always very popular at parties and I`ve already offered it in an alcohol-free version, as it were as a vitamin bomb for pregnant women (omit tequila and use mineral water instead of sparkling wine).