Heat olive oil in sauté pan over medium heat and add bacon to pan. Cook until bacon is crispy then remove from pan and drain on towel. Leave rendered bacon fat in pan.
Add onion, cabbage, garlic, salt, and pepper to pan cook for 2-3 minutes.
Pour in stout beer and allow to reduce by half.
Add heavy cream, green onion to pan and simmer to reduce cream by half.
Stir in parmesan cheese and remove from heat. Fold in bacon and sage.
In a bowl stir in breadcrumbs, olive oil and cheddar.
Portion cabbage mixture on each oyster then top with a portion of cheddar and crumb crust.
Heat oven to 400 degrees F. Bake for 6-8 minutes until top is browned then serve.