1 Piece sushi grade tuna loin (about 1 pound -- cleaned)

2 Tablespoons black sesame seeds

2 Tablespoons white sesame seeds

2 Tablespoons chopped shallots

1 Sprig fresh thyme

1/2 Tablespoon cracked black pepper

1 bay leaf

1/2 Cup white wine

1/4 Cup heavy cream

1 Stick butter (cut into small pieces -- at room

temperature) 1 Tablespoon wasabi paste -- diluted with 1/2

tablespoon rice vinegar

Season tuna with salt and pepper on each side. Combine black and white sesame seeds and roll tuna in mixture. Set aside. In a saucepan simmer shallots, thyme, pepper, bay leaf and white wine. Reduce slowly until dry. Add heavy cream and bring to a boil. Slowly whisk in butter, one piece at a time. Season with salt and pepper, strain, and keep beurre blanc warm. In a large skillet sear tuna, lightly brushed with olive oil, for 2 minutes on each side. Slice into 12 medallions. Serve immediately on serving plates. Drizzle with beurre blanc and wasabi mixed with the rice vinegar.