My company purchased an oven. I recorded it as an expense to the P&L statement. How would I then add it to the fixed asset balance sheet account for depreciation?

You don't count an oven as an expense. The reason you're having trouble figuring this out is because it should not have been an expense to begin with. Depreciation is an expense, so if you start depreciating it, you're expensing it twice and that doesn't work.

You need to credit it back out of the expense and debit it into the fixed assets. (Under like equipment or kitchen equipment if you have a such category.)

Thank you. That was very helpful.

You're welcome. :-)