Blanch the parsley and spinach in a saucepan of salted boiling water until bright green, 10-15 seconds. Drain and refresh in a bowl of ice water.
Drain and place the parsley and spinach in a food processor. Add the scallion, celery, capers, and lemon zest; pulse until finely chopped. Add 1 Tablespoon Pernod and some salt and pepper to taste, pulsing a few times.
Preheat the oven to 475°F. Line two baking sheets with pieces of crumpled aluminum foil. This allows the oysters to sit flat and not tip over.
In a bowl, stir together the breadcrumbs and chopped bacon. Set aside.
Carefully shuck the oysters with a shucking knife; hold the oyster wrapped in a towel in one hand, and slide the tip of the knife into the hinge of the oyster, located at the thin end where the top and bottom shell meet. Once the tip of the knife is in the oyster, wiggle the knife back along the length of the shell to sever the adductor muscle that is attached to the top shell, opening up the oyster.
Carefully scrape the oyster meat onto a tray lined with paper towels; reserve half the shells.
Spoon the parsley-spinach mixture into the reserved shells and return the oyster meat on top. Top with the breadcrumb mixture; dot with butter. Place the oysters on the foil on the sheets.
Transfer the baking sheets to the oven and bake the oysters until golden brown and bubbling, 10-15 minutes.
Meanwhile, melt the remaining butter with the remaining Pernod in a small saucepan.
To serve, spoon the melted butter mixture over the oysters.
