Place the salmon steak on a work surface.

Insert the knife between a belly flap and its inner membrane. Carefully cut the membrane away from the meat.

Repeat for the other belly flap and along the spine, removing any pin bones with tweezers.

Cut the meat away from the spine on both sides.

Trim the inner membrane from both belly flaps.

Remove the spine with a final cut. 

Slide the knife between the skin and meat of one belly flap, leaving the skin attached at the base.

Fold the flap into the space where the spine was.

Curl the other belly flap under to form a round shape.

Wrap the loose skin around the rolled steak.

Hold the roll and tie it with butcher's twine using an overhand knot, tightening securely.

Preheat the oven to 450 degrees F. Line a baking sheet with parchment paper and lightly grease with 1 teaspoon olive oil.

Pat the steaks dry with paper towels,  brush with olive oil and season with salt and pepper on both sides.

 In a medium bowl mix together orange juice, honey, soy sauce, and chili flakes.

Dip rosemary sprigs into a bowl of orange marinade and brush the steaks.

Place 1 slice of orange on each steak.

Arrange the rosemary sprigs around the steaks on the baking sheet.

Bake in the center of the preheated oven until just cooked through, about 12-15 minutes.

In a medium skillet, melt the butter. Add the remaining marinade and a small sprig of rosemary. Bring to a gentle simmer, then add the flour slurry. Cook over medium heat, stirring constantly,  for 2-3 minutes until the sauce thickens. Remove from the heat and keep aside.

To serve, drizzle the steaks with the prepared sauce. This dish is best enjoyed over rice, noodles, or steamed vegetables.