As posted on Boston.com. Adapted from Rendezvous.
Serves 4 as an appetizer

• 1 pound boneless bluefish
• Olive oil (for sprinkling and frying)
• Salt and pepper, to taste
• 2 tablespoons olive oil
• 1 jalapeno chili pepper, cored, seeded, and chopped
• 1 medium onion, finely chopped
• 1/2 bulb fresh fennel, finely chopped
• 1 stalk celery, finely chopped
• 1 1/2 cups mayonnaise
• 2 tablespoons sriracha or other hot sauce
• 2 slices (1-inch thick) French bread or 1 small dinner roll, torn up
  

1. Set the oven at 400 degrees. Set the fish in a baking dish (skin side up). Sprinkle with oil, salt, and pepper. Roast the fish for 12 to 15 minutes or until it is cooked through. Leave to cool. Flake the fish, discarding the skin and any bones.

2. In a large skillet, heat the oil. When it is hot, add the chili pepper, onion, fennel, celery, salt, and pepper. Cook, stirring often, for 10 minutes or until the vegetables are softened.

3. Meanwhile, in a bowl, whisk the mayonnaise with 1 tablespoon of the hot sauce. Taste for seasoning. Add the remaining hot sauce, 1 teaspoon at a time, until it is the right heat for your taste. Transfer 3/4 cup of the mayonnaise to a serving bowl.

4. In a food processor with the motor running, pulse the bread into crumbs. Add the fish and pulse until it is well mixed. Add the onion mixture and remaining 3/4 cup of the mayonnaise. Pulse until well mixed.

5. Remove the work bowl from the processor stand. With your hands, shape the fish mixture into 4 patties.

6. In a large nonstick skillet, heat enough olive oil to barely cover the pan. When it is hot, fry the fish cakes for 5 minutes on a side, turning once, until they are crisp and golden. Serve with the spicy mayonnaise.