They send you a random sandwich
No longer acceptable only when eating dumplings in Chinatown, the act of ordering food without knowing what's in it's exactly the idea of Randwiches, a sandwich service started by two roommates/amateur chefs/music industry escapees who took home the title at the Brooklyn Bacon Takedown despite not bringing home the bacon from the music industry. The concept's simple, yet cool enough they just received a grant: order a sandwich, and they'll deliver you one, but you won't know what kind until it shows up. How it goes down
Ordering: You'll have to predict your hoagie hankering in advance, because orders must be placed two days ahead of time by using their soon-to-be-unveiled order form. Assuming you pay them using either PayPal or Venmo, they'll show up at the agreed-upon time with a paper bag sporting a handwritten list of the contents, none of which are "Make sure you eat your apple, bubby!!".
Eating: Never store-bought, previous 100% homemade efforts include a roast beef joint w/ pickles, jalapeno mustard, wild mushrooms, and Pecorino; a bacon & Chardonnay jam number made with homemade KFC-spiced chicken; and chicken adobo w/ arugula and the mashed plantains/pork cracklin' spread known as mofongo, which explains the popular maxim "Mofongo, mo' problems with your cholesterol"
Tipping: Each bread bomb is just $7, and in lieu of a tip they ask that you refer them using your social media channels, because as long as they're hooking you up with random sandwiches, they might as well send 'em to your random hook-ups.