In a large sauté pan on medium heat with 1 tablespoon of olive oil, add the onions and garlic and cook for 4 to 5 minutes while constantly stirring.
Once they are lightly brown, add in the cream and reduce until the cream is the consistency of Alfredo sauce.
Once the heavy cream is to the desired consistency, add in the baby spinach and cook until mixed in and slightly wilted.
Season the mixture with salt and cracked black pepper. Set the pan aside.
In a separate medium sauté pan on medium-high heat with 1 tablespoon of olive oil, add in the raw oysters (without the shell) and sauté for 1 to 2 minutes to slightly cook.
Add the Chardonnay wine to deglaze the pan while you sauté the oysters for 1 to 2 minutes.
Place the oyster shells on a sheet pan and divide the cooked oysters among the shells. There should be 1 oyster for 1 shell.
Top each oyster with a little bit of the cream-baby spinach mixture followed up with julienne prosciutto ham and shredded asiago cheese. Divide all the ingredients between the oysters.
Finish by evenly sprinkling on the breadcrumbs and then parmesan cheese.
Broil the pan of oysters in the oven on high for 2 minutes or until the cheese is melted and golden brown.
To Plate: Remove oysters and shells from the pan and add to a tray along with lemon slices.
Notes
Make-ahead: These are meant to be eaten as soon as they’re done cooking.How to Store: Store them covered in the refrigerator for up to 2 days. They will freeze well covered tightly for up to 2 months. It’s best if you freeze them raw before the procedure of placing them under the broiler. To reheat frozen raw, simply place it on a sheet tray and bake it in the oven at 400° for 12-15 minutes.How to Reheat: Add the oysters to a pan, cover with foil and bake in the oven at 400° for 6-8 minutes or until hot and the cheese has re-melted.You can use frozen spinach with this recipe. Just ensure it is rinsed and well-drained.Feel free to substitute Pecorino Romano for the Parmesan.