BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) $ in Thousands				1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 28, 2023 USD ($) restaurant	Dec. 28, 2022 USD ($)	Jul. 30, 2014	Sep. 30, 2022 USD ($) restaurant	Jun. 28, 2023 USD ($) restaurant	Jun. 29, 2022 USD ($) restaurant	Jun. 28, 2023 USD ($) item restaurant segment	Jun. 29, 2022 USD ($) restaurant	Dec. 28, 2022 USD ($) item
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Total amount of outstanding debt						$ 60,000		$ 60,000
Cash available	$ 10,183	$ 20,493			$ 10,183		$ 10,183		$ 20,493
Leaves of absence and overtime pay due to COVID 19					100	300	$ 100	2,600
Number of operating segments | segment							1
Goodwill and intangible asset impairment					0		$ 0
Goodwill decrement related to dispositions of restaurants							0	0
Unrecognized tax benefits, accrual of interest or penalties	$ 0	$ 0			0		0		$ 0
Gain on recovery of insurance proceeds, property, equipment and expenses							242
Gain on recovery of insurance proceeds, lost profits, net							(151)
Received from the insurance							400
Unrecognized tax benefits, interest or penalties expenses					0	0	0	0
Percentage of cash savings in taxes realized as a result of utilizing net operating losses payable to pre-IPO stockholders			85.00%
Income tax receivable agreement income					121	(186)	(1)	(316)
Asset impairment charges						200		300
(Gain) loss on disposal of assets					(80)	42	(50)	108
Provision for income taxes					$ 2,735	$ 3,055	$ 4,686	$ 3,960
Estimated effective tax rate					27.90%	30.00%	28.10%	30.00%
Statutory income tax rate							21.00%
2022 Credit Agreement
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Proceeds from Lines of Credit					$ 2,000
Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Closed-store reserve expense					100		$ 100
Income tax receivable agreement income							(100)
Asset impairment charges					$ 100		$ 100
Supplier Concentration Risk | Accounts Payable
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number Of Suppliers | item							1		1
Supplier Concentration Risk | Supplier One | Accounts Payable
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration	30.90%	41.70%
Supplier Concentration Risk | Largest Supplier One | Purchased
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					27.80%	27.40%	27.30%	28.50%
Geographic Concentration Risk | Revenue
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					100.00%	100.00%	100.00%	100.00%
California
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant	1				1		1
Number of restaurants with ROU asset impairment charges | restaurant						1		1
Greater Los Angeles area market | Geographic Concentration Risk | Revenue
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Percentage of concentration					70.90%	70.90%	70.80%	70.90%
Closed Store
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Closed-store reserve expense						$ 100		$ 100
Fire
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant				1
Fire | Maximum
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Incurred costs							$ 100
(Gain) loss on disposal of assets				$ 100
Company-operated
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant	188				188		188
Franchised
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants | restaurant	304				304		304