Hotel Chocolat celebrated the opening of its first store in the United States — it’s on Newbury Street, of course — with a well-attended party this week. Company cofounder and CEO Angus Thirlwell was serving up sweet treats to a crowd (including Boston Foodie blogger Will McAdoo) eager to sample the Willy Wonka-worthy goods. We were interested to learn the shop offers private chocolate tastings — but by appointment only.Mark Shanahan can be reached at email@example.com. Follow him on Twitter @MarkAShanahan. Meredith Goldstein can be reached at firstname.lastname@example.org. Follow her on Twitter @MeredithGoldste.