Stuffed Fish Rolls

A nice mild fish recipe.  From Food and Drink Autumn 2010

4 Tilapia fillets, each about 175 to 210 g
4 thin prosciutto slices
1 lemon
1/2 cup extra smooth ricotta cheese
1/4 tsp freshly ground black pepper
1/4 cup freshly grated Parmesan Cheese
1 1/2 to 2 cups lightly packed sorrel leaves or baby spinach and arugula mixture
Kitchen twine
2 tbsp butter

1. Preheat oven to 350F.
2. Generously butter or grease an 8 inch square baking or gratin dish that will snugly hold rolls.  With best looking side down, lay fish on paper towels; bat dry.  Lay a prosciutto slice over each, folding prosciutto to fit as needed.
3. Zest lemon ans squeeze juice; keep separate.  Stir ricotta with pepper. Divide ricotta mixture among fillets; smooth over prosciutto.  Sprinkle with Parmesan.  Top with a layer of sorrel, pressing into cheese.  Cut 8 pieces of twine, each about 16 inches long.
4. Roll up each fillet from the short end; tie neatly on either side of middle with twine.  Trim twine ends; discard.  Place rolls seam side down in dish.  (Fish rolls can be covered and promptly refrigerated for up to half a day.  Add 10 minutes to baking time).
5. Melt butter; evenly drizzle over rolls.  Sprinkle with 2 tbsp lemon juice.  Cover dish tightly with foil.  Bake for 35 to 40 minutes or until fish at bend of roll flakes easily when prodded with a fork.
6. Mix lemon zest with a finely chopped leaf or 2 of sorrel.  Place fish onto warmed serving plates; garnish with zest mixture.