Place garlic, spinach, watercress and green onion in food processor and mix until ingredients are finely chopped. Transfer mixture to bowl.
Combine butter, breadcrumbs, Pernod, hot sauce and fennel seeds in food processor and blend. Return garlic and spinach mixture to processor and blend again.
Sprinkle salt over a large baking sheet. Arrange oysters in half shells on baking sheet, sprinkle with salt, and top each oyster with one tablespoon of spinach mixture. Sprinkle oysters with Parmesan cheese and bake for eight minutes or until golden brown.