A must-make dish for any oyster aficionado, Oysters Rockefeller is a luxurious appetizer that turns any occasion into a very special one. They're perfect to serve for Mother's Day brunch, a sophisticated New Year's shindig, or even a quiet dinner at home.
Adjust an oven rack top to the upper middle position and preheat oven to 450 degrees.
In a food processor, combine garlic and pulse until finely chopped. Add spinach, watercress, and green onions and pulse until finely chopped. Transfer to a bowl.
In food processor, combine butter, breadcrumbs, Pernod, fennel, and hot sauce. Process until blended. Add spinach mixture back to process and pulse just until combined. Season to taste with salt and pepper.
On a rimed baking sheet, pour rock salt to the depth of 1/2 inch. Arrange oysters in half shells on top.
Top each oyster with 1 tablespoon spinach mixture and sprinkle with cheese. Bake until golden brown, about 8 minutes.