In a small bowl, stir together rémoulade and cream cheese until very smooth; set aside.
In a medium bowl, combine flour, cornmeal, and Cajun seasoning. Add oysters, and toss to coat completely.
In a medium saucepan, pour oil to a depth of 3 inches. Heat oil over medium-high heat until a deep-fry thermometer registers 350°. Working in batches, fry oysters until golden brown, about 2 minutes. Drain on paper towels; keep warm.
Spread cream cheese mixture into bottom of each endive leaf. Top each with 1 fried oyster. Garnish with green onions, if desired. Serve immediately.