Now this one looks incredible. The Grove Hotel’s Formal Gardens will be the setting for a spectacular dining experience taking place from 9th June to 3rd September. Guests can choose either a nine course feast of afternoon tea, to enjoy whist sitting inside the vintage-style wicker dining baskets of a hand-crafted hot air balloon.
Dishes use ingredients freshly picked from the hotel’s Kitchen Garden and feature fun, creative twists including the iconic lobster en-croute carved at the table, and edible ‘clouds’.
Bookings are for groups of between four and six.

Located just outside Elstree, Home Farm hosts a series of wild feasting events this summer as part of its annual "At Home Live" program (also includes intimate live concerts. comedy shows and even a circus!).
Celebrated chefs, including Sabrina Gidda, Josh Katz, Noor Murad, and Social Pantry’s Sarah Turner will be joining fire-cooking expert Ben Quinn to create unique long table feasts which are accompanied by a a live jazz band and take place in a stunning setting underneath a huge ancient oak tree.
The events take place on 6th, 7th and 8th June plus the 12th September and you can even make a night of it and stay over in one of Home Farm Glamping's gorgeous Bell Tents or Yurts.

Hertfordshire’s very trendy lifestyle hotel Birch has launched a series of supper clubs taking place throughout spring and summer at its flagship restaurant Zebra Riding Club.
The Supper Club takes place in former stables of the main house, and consists of a four-course meal, with wine pairing and entertainment throughout the night. All food served on the night is cooked over an open fire only using produce grown at Birch Community and surrounding woodland.
Confirmed dates are 27th of April, 25th of May plus the 29th of June, with September dates to be announced.

Calling all party people! The Lounge by Graze Life in Berkhamsted hosts a fabulous Cabaret Brunch on selected Saturdays each month. For £45 you get a Brunch or Traditional Graze Board, a glass of Prosecco on arrival, and an hour of incredibly fun and eccentric Cabaret entertainment, bringing pop, Disney and Westend shows to life!
After the cabaret, and presumably a few more glasses of bubbly, the party continues with an hour’s DJ set playing 90's, pop and club classics.

Although not officially in Hertfordshire, this option is just a step over the border into Bedfordshire and is too good to exclude from my list.
Experience Normadic host group feasts located in hidden woodland locations amongst the Chiltern Hills. Guests join a guided tour of the estate hosted by the resident forager and then sit at theatrically set tables set amongst the trees, to enjoy dishes that feature foraged foods cooked over an open flame on-site in the wild kitchen.

Independent gastro pub The Plough currently holds 2 AA Rosettes so you know their food is going to be top notch. On the last Tuesday of each month The Plough hosts a supper club with different themes or chef collaborations.
Dating back to the 17th century, this wonderfully historic pub is a firm favourite for local foodies, as well as attracting customers from further afield.
The next event will take place on 2nd May, with a collaboration with chef Nathan Outlaw, who runs a two Michelin star restaurant in Cornwall and has appeared on television shows such as BBC's Great British Menu and Saturday Kitchen. Following dates are 23 May, 27 June and 28 July.