Gather all ingredients before starting the recipe.
Glaze
Season cod with kosher salt to taste and set aside until ready to cook.
Mix together 1 tsp brown sugar and 1-2 tbsp orange marmalade, a dash of water to make it spreadable and set aside until ready to cook cod.
Cooking Cod
Spread marmalade glaze on all sides of the cod.
Heat a small skillet over medium-high heat.
Add cod fillets to hot skillet and cook for 2-3 minutes or until the cod gets a nice golden-brown color.
Flip to cod and cook for another 2-3 minutes or until the cod flakes easily with a fork and is a golden-brown
Sauce
While the cod is cooking, mix 4 tbsp Hellman's mayonnaise, 3 tsp apple cider vinegar, 1 tsp Dijon mustard, and any remaining marmalade in a small saucepan and heat until it is warmed.
Serving
Spoon a layer of sauce in the center of a serving plate, set the seared cod on top, then garnish with 1 whole orange cut into segments and fresh parsley leaves for a clean, bright finish.