The renowned chef Alain Ducasse has opened his latest restaurant concept, Rivea, at the Byblos Hotel in Saint-Tropez—just in time for the summer season. It replaces the chef’s restaurant Spoon. The Michelin three-starred Ducasse has created a menu that blends French and Italian influences with local seasonal ingredients. Starters include sardine comfit in a soup of basil, chickpeas, and sheep curd; entrées range from swordfish steak with panisses, sautéed gamberoni and vegetables to handmade pasta wi…