One sells a cheeseburger whose patty is 100 percent cheese, another sells meatballs the size of baseballs and a third tempts palates with insects on a skewer.

Belgium takes its food seriously — and adventurously — so when the American-style food trucks rolled in, there was little doubt the result would be a bit different.

"Our crickets on a stick are our best seller," said Bart Smit, co-owner of the food truck Microbar. "They aren't really crickets, they're grasshoppers, but it sounds better to say cricket on a stick."

At a recent food truck festival in the port city of Antwerp, young entrepreneurs cooked up a multi-ethnic storm. The wafting aroma of everything from Indonesian satays to BBQ pork and stone-oven pizza drifted into the city center, drawing throngs of foodies to the Antwerp quayside.

A brick-and-mortar locale was once the only place most aspiring restaurateurs could start a business. Losses were great when it didn't work. Recently, food trucks have radically changed the equation: With a working vehicle and a small amount of capital, it's possible to operate a one-person eatery.

The trucks themselves come in all shapes and sizes. Thomas Serros, originally from San Francisco, has a specially outfitted bicycle he pedals to outdoor markets to sell his homemade tacos.

"I came to Belgium and worked for a bank, then I realized I couldn't speak all the languages they required," Serros said. "So, I had to think of something else to do."

One constant that runs through nearly every food truck in Belgium is the quest for locally sourced, organic ingredients.

"It's important to start with a good product," says Gilles Leenknegt of meatball vendor Balls & Glory. "We source all of our pork from the family business, so we follow it from there and directly to the customer."

Their enormous pork meatballs have liquid centers in a variety of flavors. One has peas and mint, another three cheeses, a third truffle mushrooms. Demand was so great during the Antwerp festival that the meatballs ran out, but customers were patient enough to wait in line for the next batch.

Normally insects are not something you want to find in a food truck. But the bugs sold by Microbar are different, the owners say — and by the look of the lines, customers agree.

"These are special grasshoppers," says Smit. "They're raised for human consumption and farmed locally."

Grasshopper isn't the only critter on the menu; there are also mealworm pancakes and eggrolls.

Martine Vander Poel makes frequent runs to Belgium from the Netherlands in her food truck called Just Say Cheese. Out of a small trailer, decorated to look like a barn, she serves a meatless cheeseburger that is coated in tempura batter, deep-fried and topped with spinach, spring onions and balsamic vinegar.

"I really just do it for the fun," she said. "You don't get rich here."