Malgorzata Lewicka was purposefully left out of the food order by bosses at the car dealership she worked at, according to the tribunal.
That tribunal heard that managers at the Hartwell Ford car dealership would ask staff for their takeaway orders once each month and buy them whatever they wanted, be it fish and chips, pizza, or other fast food, the Mirror reports.
However, Ms Lewicka says they deliberately didn't ask her for an order in the aftermath of accusations she made against another member of staff of sexual discrimination.
Back in March 2018, she complained about her rate of pay, as well as her working hours, alleging that sexual discrimination was taking place.
After an investigation, one member of Hartwell staff was issued a final warning after the company found they had committed gross misconduct.
Ms Lewicka claims she was then left out of the monthly staff takeaway lunch, which took place on the last Friday of every month.
She said that 'other employees were asked but she was not asked if she wanted to order food or participate'.
Hartwell had claimed Lewicka was not asked for her lunch order because she'd finished at 1.00pm, though the tribunal refused this as an excuse.
They also heard about her colleagues stopped speaking to her and put the phone down on her if she answered calls.
In January 2019, she was made redundant after being told her role would have to be full time.
Ruling, Judge Jennifer Bartlett said this was sexual discrimination as Lewicka was a single mother and received less favourable treatment for working part time.
She had worked for Hartwell in Watford from May 2014 until moving to their Hemel Hempstead site while the Watford dealership was rebuilt between November 2016 and April 2018.
Bartlett said Lewicka's exclusion from 'Pizza Friday' was tantamount to sexual discrimination.
She said: "We accept that the lunches may have been ad hoc and they were informal.
"However [Ms Lewicka] gave clear evidence that at Hemel a manager went around the site taking lunch orders and that she was included.
"However when she moved to Watford she was not asked if she wanted to order or participate whereas other colleagues were.
"She could have been asked if she wanted to join in."
Bartlett added: "[Miss Lewicka] as a single woman with child care commitments has suffered a disadvantage from [Hartwell's] requirement that Service Advisors work full-time namely she was selected for redundancy and dismissed."
Lewicka was awarded £23,079 which included compensation for loss of earnings and injury to feelings.