Jill Savory tried to buy food online to avoid crowds of people panic buying from supermarkets amid the coronavirus outbreak.
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The mum-of-two believed she ordered a bag of the veg, but was stunned to receive a single sprout.
Jill, from Durham, shared the images online as well as the receipt for her order showing she had only been charged for the one sprout.
The label on the bag showed it weighed 0.028kg and costing only three pence.
Sainsbury's confirmed with The Sun Online the order was made for a single item.
Jill, from Durham, said: "I have been going to the local shop for bread, milk and basic things, trying not to leave the house.
"I never do online but did not want to go to the shops. Took me ages to get a slot.
"Even the delivery man said: 'I don’t know why, but they sent you one sprout.'"
Jill's Facebook post has received more than 20,000 likes.
She wrote: "Got to laugh. I done my online shop today and they only sent me one Brussels sprout.
"I obviously wanted a pack, not just one."
One person wrote: "Don’t eat it all at once."
Another added: "I want you to cook this up into something amazing with this being the focal point of your plate."
One said: “You are going to have to be inventive with that.”
Brits have been told to stop panic buying as many supermarkets have had ration how much people are allowed to buy.
Sainsbury's, Tesco and Asda set a limit of three for any item and two for essential products, such as toilet roll and handwash.
Extra staff have also been drafted in to help with the demand.