What to eat: Hmm, let's see . . . how about meatballs? Co-owner Mike Antinore wisely offers $3.50 single-meatball sliders, in case you're not ready for a whole hoagie, which runs $8.50. We find that two sliders and a bag of chips gets the job done, but he also offers a $10 lunch special: hoagie, chips and a bottle of water. The balls are pretty big.

Don't miss: The menu changes, but the original "Mama's Ball" is a blend of beef, pork and veal in a homemade sauce. Also try the "Datz-A-Spicy Ball," with hot sausage and jalapeno cheese. And, if you can handle it, they'll add some hot sauce made from jalapenos, habaneros, serranos, poblanos, long hot peppers, crushed red pepper and a ghost pepper (look it up).

Getting crazy: Keep an eye out for curveballs like the "Rabe Father" (ground turkey and broccoli rabe stuffed with asiago cheese and served with homemade sauce and pesto) or the meatball with bacon and blue cheese. Or a veggie ball. "We're definitely trying to be innovative and change up our balls," said Antinore, who opened the truck in July with co-owners Bill and Whitney Proudman. "For so many centuries, nobody changed it. It's always been a regular meatball, end of story. But there's a meatball revolution going on in this country and we're going to try to have a revolution within a revolution."

Where: Mama's Meatballs moves around a lot because, let's be honest, the same lunchtime crowd isn't going to feast on meatballs every day of the week. They've served everywhere from LOVE Park to the Navy Yard.

Social stuff: Check Twitter (@MamasBalls) or Facebook ("Mama's Meatballs") to get the location.