You cannot claim this expense under employment expenses as you did not incur it while entertaining a client.
According to the Canada Revenue Agency (CRA),
"Food and beverages - You can deduct food and beverage expenses as long as your employer requires you to be away for at least 12 consecutive hours. To qualify, you must be away from the municipality and the metropolitan area (if there is one) of your employer's location where you normally report for work. These amounts are subject to the 50% limit discussed below in the section called Employment expenses.
The 50% limit also applies to the cost of food, beverages, and entertainment you paid for when you travelled on an airplane, train, or bus, as long as the ticket price did not include such amounts.
Entertainment expenses - You can deduct part of the cost of entertaining clients. Expenses you can deduct include those for food, beverages, tickets, and entrance fees to entertainment or sporting events. You can also deduct tips, cover charges, room rentals to provide entertainment, such as hospitality suites, and the cost of private boxes at sports facilities.
The most you can deduct is 50% of the lesser of:
Thank you for choosing TurboTax.