In a large skillet, saute onion in butter until tender. Add spinach; cook and stir until wilted. Remove from the heat; stir in cheese, lemon juice and pepper.
Spread kosher salt into 2 ungreased 15x10x1-in. baking pans. Shuck oysters, reserving oyster and its liquid in bottom shell. Lightly press oyster shells down into the salt, using salt to keep oysters level. Top each with 2-1/2 tsp. spinach mixture.
Bake, uncovered, at 450° until oysters are plump, 6-8 minutes. Serve immediately.
Oysters Rockefeller Recipe Tips
How many oysters do you need per person?
If you're serving Oysters Rockefeller as an appetizer, plan on 2 to 3 oysters per guest. For other oyster recipes, serving sizes may vary.
How do you know when oysters are done?
Oysters are done cooking once they become nice and plump, and the edges start to curl.
What goes well with oysters for dinner?
A thick, chewy bread always goes well with oysters! Try out our Crusty Homemade Bread recipe to really impress your guests.
Research contributed by Sarah Fischer, Taste of Home Culinary Assistant