For salad, cut bottom off frisée, wash and arrange on a platter. Sprinkle with chopped green onion and walnut pieces.
For vinaigrette, whisk red wine vinegar with Dijon mustard, honey or sugar, garlic and salt and pepper until fully blended.
Slowly pour in oil, whisking constantly. Vinaigrette can be prepared in advance and whisked to emulsify. Drizzle over salad.
To warm cheese, preheat oven to 375 °F. Place Camembert or Brie on a tray and bake whole for 12 minutes.
Remove and pass around table to spoon out, warm, next to salad.