This is stunningly good. I got the idea after eating in Japanese restaurants where oysters and sea urchin roe were broiled under a topping of plain mayonnaise.
Serves 6 as an appetizer, 3-4 as a main course

1 cup

mayonnaise (commercially prepared)

240 ml

1 Tbsp.

prepared wasabi paste

15 ml

24

freshly shucked oysters on the half shell

24

1 Tbsp.

toasted sesame seeds

15 ml

2

green onions, finely chopped

2

Combine the mayonnaise and wasabi paste until well blended.
Choose a large, rimmed pan to cook the oysters on. Crumple a piece of tinfoil twice as large as the pan you are using to broil the oysters in and then stretch it out to fit the pan. You want the little hills and valleys of tinfoil to hold the oysters securely, so don't smooth it out. Spread about 1 tsp. (5 ml) of the paste over each oyster, sprinkle with the sesame seeds and arrange on the pan. The oysters may be prepared up to an hour in advance. Cover and refrigerate.
Preheat the broiler. Broil the oysters until the mayonnaise picks up brown spots, 3-4 minutes. Sprinkle with the green onion and serve on the half shell.

From Screamingly Good Food, © 1997 Karen Barnaby, Whitecap Books