By Sherron Lumley. Delicious old-fashioned donuts are on display behind Nasima Rahman, who stands at the counter of Sesame Donuts, greeting her morning rush of customers with a warm smile. “My wife throws in extra donut holes,” says Mohammed Rahman, her husband, “because making people happy is very important to us.” This emphasis on customer service has led to a quickly growing small business, and recently Rahman has been courted with offers for ample new credit lines, far more than the...