The U.S. restaurant industry grew at a solid pace over the past two years despite major challenges from higher borrowing and raw material costs. Higher personal income has been one of the key reasons Americans have been spending lavishly on eating out.The Commerce Department reported earlier this month that restaurant sales showed impressive growth in September, boosting overall retail sales.Given the bright outlook, investing in restaurant stocks, such as Dutch Bros Inc. (BROS) , Brinker International, Inc ...