An extremely rich meal for the holidays
Using an oyster knife, pry open the shells and remove oysters. Discard top shells; scrub and dry bottom shells. Drain oysters, reserving the oyster liquor.
In a large saucepan, melt the butter. Add spinach, onion, parsley, bread crumbs, bacon bits and salt. Cook and stir constantly for 15 minutes. Remove from heat.
Press the spinach mixture through a sieve or food mill; let cool. (Mixture may be made ahead of time and refrigerated until ready to use.)
Preheat oven broiler. Line an ovenproof plate or platter with a layer of rock salt about 1 inch deep. Moisten the salt very slightly. Set oysters in the rock salt, making sure they are level.
Place a little of the reserved oyster liquor on each oyster. Spoon equal amounts of the prepared spinach mixture over each oyster and spread to the rim of the shell. Top off with alfredo sauce.
Bake approximately 8 to 10 minutes or until the topping bubbles. Watch carefully. Garnish with parsley sprigs and lemon wedges. Serve immediately.