With Spain mired in its worst financial crisis in almost six decades and concern about a government default swirling, you’d think there’d be little reason to party. But on a recent sweltering evening in Madrid, Juan Caldera was busy socializing at a local restaurant as he munched on a bacon and brie sandwich washed down with a cold beer. Thankfully for the 23-year-old law student, a big night out comes at a small cost at trendy 100 Montaditos, a restaurant chain that’s taken Spain by storm. The traditional 5-inch sandwiches that give the chain its name some nights cost just €1 ($1.42), while beer is €2, the perfect tab for a nation coping with a 21 percent jobless rate, the highest in Europe. “We love the price and the atmosphere,” says Caldera. “I come with friends once a week and have three to seven montaditos. There are so many people, you even have to line up for a few minutes to grab a chair.”

The chain has doubled its number of restaurants across Spain since 2007, to 200, and now it’s setting its sights on the U.S. Restalia Grupo de Eurorestauración, the parent company of 100 Montaditos, aims to open 4,000 American stores in the next five years. As it does in Europe, the chain will chase that goal with a combination of company-owned stores and franchised restaurants. It would be a faster expansion than that of Starbucks (SBUX), which didn’t have that many outlets in the U.S. until three decades after its first shop opened.