Chef Michael Scelfo, owner of Alden & Harlow and Waypoint, isn’t afraid of getting his hands dirty. The restaurateur is opening his third spot, Longfellow Bar, a finger food-inspired concept set to take up residence above Alden & Harlow in mid-December. With fun nods to fast food and molecular mixology, the menu invites patrons to get messy through a no-utensils policy, unless specifically requested.

“I really love the authenticity of eating with your hands and literally breaking bread with someone,” Scelfo says. “I want people to make a mess and pass things and tear them and share them, and that’s what it’s really all about because I truly feel like that’s the best part of a meal. Connecting with someone versus all the pomp and circumstance of a formal setting.”

The menu will include shareable small plates like a warm rye pretzel served with a cheddar smear, mustard seeds and topped with a heaping pile of colorful pickles, as well as rellenong hipon stuffed with shrimp and port sausage and served with a smoked honey nam prik. Bigger bites include two hamburgers, including Alden & Harlow’s beloved “secret burger.” The kitchen will serve lunch on weekdays and dinner every night. For the beverage program, a number of cocktails feature names taken from the tracks of some of the employees’ favorite albums, such as the Reason to Believe, a mixture of Batavia Arrack, coconut milk, Thai chili, lemongrass and kaffir lime, and the State Trooper mixing fermented clementine, pisco, citric solution and egg white.

The two-floor interior includes walls wrapped in walnut, a roof-deck patio that accommodates 15 and a white marble bar with blue-and-brass tiles. The 75-seat space will also feature a chef’s table directly across from the front entrance, where guests might spot Scelfo whipping up a meal.

“I started off my career in Boston cooking bar food,” Scelfo says. “To revisit that now after eight or nine years of doing more fully fleshed-out menus and concepts has been hugely satisfying. It’s been really fun to go back and see where my head’s at now when it comes to bar food and how I can create a menu that complements what we do downstairs without being completely contradictory.”

Longfellow Bar 40 Brattle St., Cambridge longfellowharvard.com

UPDATE: Longfellow Bar opens Saturday, Jan. 19.