Sébastien Castagna explains why he operates three franchises of American brand in Luxembourg. Sébastien Castagna is a serial franchisee. After having launched eight businesses under Courtepaille and Memphis Coffee licences, over the last four years in Luxembourg and in France, the French entrepreneur is about to go for more. For 2018, he is planning to operate three Five Guys restaurants and two further Osteria Pizza E Pasta businesses in Luxembourg.