What does Darrels, or a similar place, have In the kitchen?

Don't they make their own bread as well?

Overhead seems low when you don’t know what goes into a commercial kitchen. Besides the flattop/griddle or commercial sandwich press, you need refrigeration, usually in a couple of separate units.....drink cooler (or fountain set up), many storage/prep bins and tubs, pots/pans for any cooking, Cutting boards/surfaces, knives, a slicer, large volume storage tubs for bulk ingredients.....

Then we are talking about dishwashing (even if you serve in disposable stuff, you will still have plenty to wash), all of your sanitation stuff and cleaning supplies (mops, buckets, sprayers to sanitize tables, etc).

Good news, plenty of small restaurants are being driven out of business right now by Covid. So if you seriously want to do this, you will find some good deals in used restaurant goods in coming months.

Everything must be NSF Rated for commercial food service operations.

Back of the kitchen equipment:

- Walk in cooler
- Freezer two or three smaller are better than one large
- 2 or 3 or 4 burner Stove top
- Dry food pantry, including bun/bread storage area.
- storage area for linens, aprons, kitchen towels, napkins
- Meat and lettuce slicer
- Prepped food storage containers (lots of them, including lids.
- Work surface, chopping, peeling, and food prep.
- Prep sink, with industrial quality disposal unit
- Dish washer with drain area
- Storage area for pots pans and depending on your serving plan - dishes
- Storage closet for mops, brooms, cleaning chemicals, etc. for kitchen and perhaps separate restroom cleaning supplies storage
- Trash disposal space

Somewhere:

Grease trap for plumbing system
Used Grease storage

Outside:

- Trash disposal area
- BBQ Pit or smoker (if those items are on the menu)
- Nasty stuff washing area
- Used grease storage

Kitchen (Items required must match menu):

- stove(s) with hood
- Flat top with hood
- fryer(s) with hood
- any specialty items your menu requires (pizza oven, regular oven, steam table, steamer, soup tureens, steam cooker, microwave, etc.)
- fried stuff holding space with heat lamps
- Refrigerated storage
- Frozen storage
- Food dressing, plating area, with refrigerated pan/bin holding capability for lettuce tomatoes, condiment etc.
- Grease filtering equipment, if not built into the fryer.
- Heated end of line staging area for completed orders
- Kitchen storage area - pots, pans, knives, spatulas, etc.

Front area:

Soft drink service
Coffee pot
Milk Shake service
Ice cream service
Condiment storage
Spoon, fork, knife storage

I am certain I have forgotten several things. This is not a simple thing.

You want to be able to produce multiple items and shape your recipes around the equipment you have. It is easy to buy a sauce pan or sauté pan, but you will need multiple pans of each type used to run a busy kitchen and someone (not the cook) to keep them clean.

If you are serious OP you start off with a food truck. Everything you need for sandwiches you can put in a food truck. Obviously you aren’t doing beers and happy hours, but get your food down first.

You can drop a million on a commercial kitchen easily but at the same time and mom and pop place in a small town has very little of that.

About 20 microwaves

Yes - all of these costs must be considered too.

I never intended to say you can't open a restaurant with a Home Depot yard building and a crockpot, but those who succeed have a better chance if they have a very good menu, a very good location, a very good business plan and a very good bank balance.

Shame on me for sharing my opinion, but I'll still say It isn't easy and many/most will fail. Even those with lots of experience.

You need to understand that going in, and then take the plunge if you still feel you must feed people for a living.