Corned beef. Rye bread. Mustard. That’s the way it should be, at Parkway Deli in Silver Spring. (Alex Baldinger/THE WASHINGTON POST)

It’s easy to overcomplicate a deli sandwich. But if you follow three simple instructions, you’ll never be let down: Deli meat of choice. Brown mustard. Rye bread. Fin.

There are exceptions, like the reuben, which adds Russian dressing and sauerkraut. But there are limits, too: Call me old school, but there’s something a bissel meshugga about a deli sandwich that’s Old World enough to include gribenes — crispy chicken skins for those of you who didn’t grow up with a Jewish grandmother — along with avocado (avocado?!).

True deli should be simple and sizeable, so while tonight’s opening of DGS Delicatessen is welcome news, there are plenty other local options if your definition of a sliced meat sandwich is bread + meat + mustard.

Loeb’s Delicatessen: Downtown’s original source of corned beef, chopped liver and marble rye.

Parkway Deli: The Montgomery County staple draws huge weekend crowds who graze at its pickled vegetable bar.

Chutzpah Deli: A Fairfax strip mall hides what’s probably the area’s largest deli sandwich, a 40-ounce reuben.

Wagshal’s: Seriously amazing pastrami in Spring Valley.

Roy’s Place: Hundreds of sandwiches in Gaithersburg, including every combination of sliced deli meat you can imagine. (And some sandwiches that have nothing to do with deli.)

Attman’s Deli: The legendary Baltimore deli is opening a second location in Montgomery County by mid-2013!

What’s your deli of choice? Speak up in the comments.