Salt, Pepper and Sugar. They're the three seasonings Shirley Sharpe depends on to create simple, honest, straight forward food and plenty of it. Just across Route 321 from Watauga Lake, one of the nation's most beautiful bodies of water, sits a plain cinder block structure, peinted white, with an add-on wooden porch, straight-back rockers, and whirring ceilings fans. Shirley's and her husband Grant once sold gasoline there; but after the 1970s energy crisis, they methodically devised a plan to abandon motor oil and stock up on Crisco. And in 1990 Shirley's Home Cooking opened, with three tables. At first it started at a trickle, but as word spread about the tastes of the mountains that covered those tables, addresses in North Carolina, Virginia, England, and Ireland began to appear in the puple address book guest book.