Mr Sou has lived in New Zealand since 2001.
Having trained as a professional chef in Cambodia, his home country, he then worked in hotels and ran bakeries in Auckland.
He shifted south to escape the pressures of large city living - first to Feilding and then early last year to Foxton when he purchased his bakery.
Mr Sou's success mirrors that of other Cambodian Kiwi bakers who have made the pie competition their own in recent years.
This year's Supreme winner was Taupo-based Lee Ing for a gourmet meat pie. Last year's Supreme winner, Tauranga-based Patrick Lam, this year received awards in five pie categories. Word got around Foxton quickly after Sam's Bakery's competition success.
When the Horowhenua Chronicle visited mid-morning, two trays of pies had already sold out and a small queue of customers wanting bacon and egg pies was asked to come back once the new batch had cooked.
Mr Sou said they generally sold 200-300 pies a day and their success was likely to increase that number.
Mr Sou saved this reporter the last bacon and egg pie of the morning, and after scoffing it down at a comfortable and sunny window seat in the café, we can - totally impartially, of course - report it is well worth a visit to Sam's Bakery and Café.