Fast-casual chain Steak 'n Shake said it has restored beef-tallow French fries to its menu and begun accepting Bitcoin for customer payments, marking a return to what the company called its “basics” while adding a digital-currency option at the register. The company framed the menu change as an effort to reconnect with long-time patrons who favored the original cooking method. The move to accept Bitcoin extends a trend among U.S. restaurant brands experimenting with cryptocurrency transactions to attract tech-savvy diners.