1 bulb fennel, cored and thinly sliced
1 large onion, thinly sliced
4 large cloves garlic, chopped
1/2 cup good quality black and green olives, pitted and chopped
2 pounds cod fillets, cut into 4 portions (get thick pieces from the center cuts rather than tail-end pieces)
Salt and pepper
1/4 cup flat leaf parsley (a generous handful), chopped
Extra virgin olive oil (EVOO), for generous drizzling
Crusty bread, to pass at table
Pre-heat the oven to 400°F.
Rip off four sheets of parchment paper, each a little over a foot long. Make layered stacks, dividing the fennel, onion, garlic, olives and cod among the parchment pieces, working in the center of each piece of paper. Season the cod with salt and pepper and top with parsley. Drizzle EVOO liberally over the fish portions. Fold the top and bottom edges together and crease several times, then crease up the ends of the packets. Arrange the packets on the baking sheet and place in the center of the hot oven.
Bake the packets for 20 minutes. Serve one packet per dinner plate and cut open at the table. Cut the lemon into wedges and serve to squeeze down over the hot fish.
Pass bread at the table to mop up the cooking juices in the sack.