Lavender farmer William Alexander said the herb, which comes from the mint family, could be used with everything from crème brulee to meat and fish.
A two-day festival at his farm in Kent, had lavender-flavoured cheesecake, ice cream, chocolate and cordial available for visitors to try.
"It's an incredibly versatile herb," the Sevenoaks farmer said.
Castle Farm now has 50 acres of lavender in flower, which is being cut by hand for drying.
The herb has been used for medicinal purposes since the middle ages, and has been used for soap and perfume since Victorian times.
Mr Alexander said: "It's used in aromatherapy and perfumes, and what we are celebrating is using it as an essence in cookery and foods."
His wife, Caroline, said this year was the first time the farm had produced lavender essence to be used as a cooking ingredient.
She said the farm had cooked an entire lunch menu using the ingredient to show how it could be used, which included main courses of chicken with lemon and lavender sauce, and beef cooked on a bed of lavender.
And she said another favourite recipe used "tart fruits like a gooseberry or a rhubarb with just a few drops of lavender essence".
Chef Victor Hugo, who sampled the new flavour, said: "It's delicious, quite subtle, but really delicious. I'm just waiting for the dessert."
Lavender picker Raj Kang said she was enjoying her holiday job picking the herb.
"It's therapeutic, you get a good night's sleep ... it's just enjoyable," she said.
Events during the festival on Saturday and Sunday included guided tours of the lavender fields, aromatherapy demonstrations, tastings and bee-keeping displays.