Baked Oysters from CCA

I saw this recipe come thru from a Coastal Conservation Association email and thought it looked good..
Featured Recipe: Simple Baked Oysters 

Ingredients OYSTERS: 2 dozen fresh, unshucked oysters 3 c rock or ice cream salt FILLING: 1 12 oz package frozen chopped spinach, thawed 4 strips bacon 1 c yellow onion, diced 3 cloves garlic, minced 1/4 c celery, diced 1 stick salted butter ½ tsp salt ½ tsp black pepper 1 c panko bread crumbs 1/3 c grated Parmesan cheese, plus more for topping Lemon wedges   Directions: OYSTERS: Preheat to 450 degrees F. Fill an ovenproof serving dish large enough for all the oysters with the rock salt. Nestle oysters in it as you shuck them. This will prevent them from tipping and also retains heat after removal from oven.   FILLING: Remove any excess water from the frozen spinach by wringing out with your hands over a strainer in the sink. Set aside. Chop bacon and add to a large skillet on medium heat. Cook bacon until crisp. Remove with a slotted spoon and set aside on paper towels for later use. To same skillet with bacon grease add onion, garlic and celery and saute about 10 minutes, or until vegetables are cooked through. Turn heat to low and add butter. Stir until butter is melted then add salt, pepper, panko bread crumbs, grated cheese, spinach and cooked bacon bits. Remove from heat and combine all thoroughly until cheese is melted. Top each raw oyster with about 1 tablespoon of topping, then sprinkle each with grated Parmesan. Place serving dish of oysters in preheated oven and bake for 15 minutes or until topping is golden brown. TO SERVE: Serve immediately with lemon wedges.