Sesame Crusted Ahi Tuna And Wasabi Beurre Blanc

• 1 sushi grade tuna loin
• 1 sprig thyme (fresh)
• 1 bay leaf
• 1 stick butter
• 1 wasabi paste with (diluted)
• 120 ml wine (white)
• 60 ml cream (heavy)
• 18 gr shallots (chopped)
• 16 gr black sesame seeds
• 16 gr sesame seeds (white)