I’ve always liked how chef Dennis Leary thinks: small. After his chefdom at Rubicon, he threw in the kitchen towel to downsize to a tiny former coffee shop in the TenderNob he dubbed Canteen, serving a small number of people a nice, small menu. From there, he's thought even smaller. His latest project is The Sentinel (37 New Montgomery St.), a New York- cool soup-and-sandwich to-go joint located in an old cigar shop across from the Palace Hotel. The kitchen is made up with nothing more than a soup warmer and a convection oven. The open space has been done up with white tile walls, accented by deep brick-red paint and a thick slate-grey soap-stone counter decorated, in Leary's signature style, with a few vintage books. Leary opened on Tuesday with limited offerings—it’s how he rolls—but eventually expects to have a few breakfast items, plus a few sandwiches and a few soups a day. Nothing too fancy pants. Just good food. I stopped by for a very good (housemade, of course) blueberry muffin, a shot of Mr. Espresso and a few questions for the 38-year-old Boston native who likes to do it his way, thank you very much.

Why a to-go shop serving breakfast and lunch items?
Because I take what I can afford without [financial] partners. And I like to get up in the morning. Plus the food sucks around here. Lee’s Deli is a fate worse than death. I wanted my motto to be, “If you don’t see what you like here, go to Lee’s.” I just want to make a decent soup.

There are no seats. Do you even have a bathroom?
There’s a bathroom in the building for employees, but I’d say go to the Palace Hotel bathroom. That thing is luxurious.

How are you dividing your time between The Sentinel and Canteen?
Here in the day, there at night.

What are you serving today?
Corn soup, cold pea soup, a smoked salmon sandwich. I’m probably jumping the gun a little bit on the corn, but I get bored of squash.

What do you see on the future menu?
Homemade yogurt, shirred eggs made in the convection oven, granola, fresh juices. I’m making a chicken salad with pine nuts, capers, raisins and all the stuff I do at lunch at Canteen that the old ladies get all worked up over. I’m selling it with endive salad and chocolate mousse. I’d like to do a hot corned beef sandwich.

What makes a great sandwich?
Proportions. Not too big.

Tell me about this hefty, old cash register.
It’s 80 years old and cost me $800 dollars. I got it from this old cash register repairman. I like all that old stuff. I also have a 1940’s tape shooter.

What’s next?
I can’t go any smaller than this, really. Maybe a taco truck. Or a cassoulet wagon.