Pare a narrow strip of peel from the middle of each potato. In a large bowl mix the oil, chopped up garlic, lots of rosemary. Add the potatoes and the potato peelings and toss well. I baked this for about 2 hours, stirring it up really good every 1/2 hour.
Mix mayonaise and wasabi together, then spread evenly over top of the cod filets. Just let that sit in the refridgerator till the potatoes are done. Broil on high till cod is done and the mayo/wasabi is a little blackened and crusty.
Serve with avacodo drizzled with lime.