ROGIER Verhoeven started in the catering business when he was a 16-year-old schoolboy in the Netherlands. But not in the traditional, modest sense of dishwasher works up to busboy, then finally finds an opening as a trainee chef. ''I rented a private farm from an antique dealer friend of mine and catered for parties of 50 or 60,'' said the joint owner/manager of the new Quo quo restaurant in Central. ''I shared the profits with my elder brother. He was the businessman, I did the back-of-the-house, creative bit. Nothing much has changed there.'' Rogier, who is now in his early 30s, says he has nurtured the idea of starting his own restaurant in Hong Kong ever since he arrived as assistant food and beverage manager at the Grand Hyatt. And with apparently little expense spared and the financial backing of partner Julian Hui (married to Stanley Ho's daughter Pansy), Rogier has finally seen the very soft opening of Quo quo (pronounced like ''cocoa'') this week. While ''Quo quo'' sounds status-conscious, and ''cocoa'' sounds plain cosy, the atmosphere in the rather hard-to-find restaurant in the new Entertainment Building is probably somewhere between the two: smoky jazz downstairs in the evenings, while a classical pianist is often the choice for the private function rooms upstairs. The unusual two-storey place is a clover leaf of roundish rooms, decorated in what Rogier describes as a ''modern colonial'' style - jade, pewter, pianos and the smell of fresh hyacinths (bulbs air-freighted from Amsterdam) throughout. The eight foundation pillars have been decorated with false ivory carvings made in the Philippines. and there are paintings, with price tags, throughout the restaurant.