Preheat oven to 375 degrees F.
In a large saute pan heat 1 tablespoon of the oil. When the oil is hot, add the sausage and cook, stirring occasionally for about 4 to 6 minutes. Add the onions
and continue to cook for two minutes. Add the garlic, and continue to cook for 1 minute.
Remove from heat and transfer to a mixing bowl and let cool. Stir in the remaining olive oil, bread crumbs, parsley and cheese and mix well. Season the oysters with salt and pepper. Grease
a 9-inch gratin
dish or pie pan
. Line the bottom with the oysters. Cover the oysters with the sausage mixture, packing it down onto the oysters. Place in the oven and bake for 8 minutes or until the top is golden brown. Remove from oven and serve warm.