PREPARATION FOR THE STEW: Strain the oysters and reserve the oyster liquor; refrigerate the oysters until ready to use for final assembly. In a medium saucepan, cook the ham in the peanut oil until lightly caramelized. Add the onion, red bell pepper, and celery and cook until caramelized. Add the garlic, red pepper flakes, and bay leaf; cook 1 minute.
Add the bourbon, lemon juice, wine, and reserved oyster liquor. Cook until greatly reduced and nearly syrupy, stirring frequently. Add the chicken stock and simmer over medium heat, skimming as necessary, until reduced by 1/2. Cool and reserve until preparing the bass. Remove the bay leaf.
ASSEMBLY: Remove the bass from refrigeration and dry thoroughly with paper towels. With a sharp knife, score an X in the skin side to prevent it from curling when the fish is cooking. Season the flesh side with salt and pepper; rub the skin side with some of the softened butter.
If serving with tomato gumbo, heat the gumbo and stir in the cooked rice as indicated in the last step of the recipe. Keep warm. Return the stew to a low heat and add the heavy cream; bring to a slow simmer.
Heat a large, heavy skillet over medium-high heat for 2 minutes. Add a film of peanut oil, then carefully lay the fillets in the pan, skin-side down. Reduce the heat to medium and press firmly on the fillets with the back of a metal spatula to flatten slightly and aid in the searing; cook 3 to 5 minutes, depending on the thickness of the fillets. When the edges of the fillets begin to show doneness, turn carefully and cook 1 minute longer. Remove the fillets and keep warm.
Raise the heat on the stew to medium-high, stir in the oysters and butter, and cook just until the oysters are plumped and beginning to curl. Remove from the heat, stir in the sage, and season with salt, pepper, and lemon juice to taste.
Warm 6 wide, shallow bowls. Place a fillet in each bowl. Spoon the stew around the fillets, dividing the oysters equally between the bowls. Sprinkle liberally with scallions and serve immediately.