FOR THE ROSEMARY OIL:
10 sprigs (each about 4 inch/10 cm long) fresh rosemary
One 17-oz./500-ml bottle extra virgin olive oil
FOR THE FISH:
Four 5- to 6-ounce/160-g skinless black cod filets (Sarah's note: I just used regular cod)
3 zucchini (each at least 7 inches/18 cm long), cut lengthwise on a Japanese mandolin into 1/16-inch/.2-cm slices (Sarah's note: I used 1/8 inch instead and that worked better for me)
4 sprigs (each about 4 inch/10 cm long) fresh rosemary
TO MAKE THE ROSEMARY OIL:
Using the back of a large chef knife, bruise the rosemary as much as possible. Place the bruised rosemary in a small saucepan with the extra virgin olive oil and gently warm the oil over medium-low heat for about 5 minutes or just until it is lukewarm. Reserve the olive oil bottle.
Remove the saucepan from the heat and set aside to allow the rosemary to infuse the olive oil with as much flavor as possible (4 to 6 hours is ideal, however a smaller amount of time will still give you a nice rosemary infused flavor). (Sarah's note: have fresh bread handy for taste testing!!)
TO PREPARE THE FISH:
Preheat the oven to 400°F/205°C. Sprinkle the fish with salt and pepper.(Sarah's note: Cod is VERY mild so season it really well to bring out some flavor) Lay about 6 zucchini slices horizontally on the work surface to overlap each other slightly and create a 5x7-inch/13x18-cm rectangle. Place 1 black cod filet on top of the zucchini slices and wrap the zucchini around the fish to cover completely.
Repeat with the remaining zucchini slices and black cod filets. Heat 1 tablespoon/15 ml of the rosemary olive oil in a large nonstick frying pan over medium-high heat. Place the fish, zucchini-seam side down, in the pan and cook for about 2 minutes or until the zucchini is lightly colored. Using a metal spatula, carefully turn the fish over, folding the ends of the zucchini slices over the fish if necessary. Don't worry if some of the zucchini slices unfold a bit. Once the fish is cooked the zucchini will soften and can be folded around the fish again before it is served. (Sarah's note: this just didn't work for me. Broiling the zucchini afterwards was the only way I could keep it all together)
Add 4 sprigs of rosemary to the pan (Sarah's note: soak these before hand or they will burn in the oven) (these will be used for garnish). Transfer the pan to the oven and bake the fish for about 8 minutes (the time will depend on the thickness of the filet), or until the fish is just cooked through.
Drizzle 1 tablespoon/15 ml of the rosemary oil around the plates. Garnish with the roasted rosemary sprigs and serve. Pour the remaining rosemary oil into the reserved olive oil bottle, discarding the rosemary sprigs, and reserve the oil for another use.